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JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

^~- _ 
VOLUME XL JANUARY, 1943 

CONTENTS 

PAGE 
The United States Army Motion Picture Service 

I. Introduction 3 

II. Construction of War Department Theaters 

C. WELPLEY 4 

III. Heating, Ventilating, and Air- Conditioning War 
Department Theaters M. D. KICZALES 24 

IV. Sound and Projection Equipment in War De- 
partment Theaters G. L. BUB 35 

V. Administration of United States Army Motion 

Picture Service R. B. MURRAY 52 

Current Literature 64 

Society Announcements 65 

(The Society is not responsible for statements of authors.) 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

SYLVAN HARRIS, EDITOR 
ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
** President: HERBERT GRIFFIN, 

90 Gold Street, New York, N. Y. 
** Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
** Executive Vice-President: LOREN L. RYDER, 
5451 Marathon Street, Hollywood, Calif. 
* Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Avenue, New York, N. Y. 
**Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 
* Financial Vice-President: ARTHUR S. DICKINSON, ' * 

28 W. 44th Street, New York, N. Y. 
** Convention Vice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
*Secretary: E. ALLEN WILLIFORD, 

30 E. 42nd Street, New York, N. Y. 
^Treasurer: M. R. BOYER, 

350 Fifth Ave., New York, N. Y. 
Governors 

*H. D. BRADBURY, 411 Fifth Avenue, New York, N. Y. 
*FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*ALFRED N. GOLDSMITH, 580 Fifth Avenue, New York, N. Y. 
*A. M. GUNDELFINGER, 2800 S. Olive St., Burbank, Calif. 
*CHARLES W. HANDLEY, 1960 W. 84th Street, Los Angeles, Calif. 
*EDWARD M. HONAN, 6601 Romaine Street, Hollywood, Calif. 
*JOHN A. MAURER, 117 E. 24th Street, New York, N. Y. 
**WILLIAM A. MUELLER, Burbank, Calif. 

*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
**H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
* "JOSEPH H. SPRAY, 1277 E. 14th Street, Brooklyn, N. Y. 
**REEVE O. STROCK, 195 Broadway, New York, N. Y. 

"Term expires December 31, 1943. 
**Term expires December 31, 1944. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motion 
Picture Engineers, Inc., 20th and Northampton Sts., Easton, Pa., or Hotel Pennsylvania, New 
York, N. Y 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1943, by the Society of Motion 

Picture Engineers, Inc. 



THE UNITED STATES ARMY MOTION PICTURE SERVICE 

A SYMPOSIUM PRESENTED AT A MEETING OF THE 

ATLANTIC COAST SECTION OF THE SOCIETY OF MOTION PICTURE 
ENGINEERS NOVEMBER 19, 1942 

At a meeting of the Atlantic Coast Section of the Society, held at the Hotel Pennsyl- 
vania, New York, N. Y., on November 19th, a group of presentations by members of 
the Army Motion Picture Service described the growth of the Service since its incep- 
tion and the details of its operation and contributions to the prosecution of the war. 

The U. S. Army Motion Picture Service, as part of the War Department, was well 
organized and had a considerable number of theaters throughout the country showing 
pictures at Army posts prior to the war, but since the declaration of war in December, 
1947 , it has been necessary to expand the activities of the Service tremendously. How 
the mergency has been met, its method of financing, and its relation to civilian 
theai are described in this symposium. Details of the management of what, in 
effet . the world's largest theater circuit are fully discussed. 

The Symposium consists of the following presentations : 

(1) Construction of War Department Theaters: By Charles Welpley, Archi- 
tect, U. S. Army Motion Picture Service. 

(2) Heating, Ventilating, and Air-Conditioning War Department Theaters: 
by M. D. Kiczales, Mechanical Engineer, U. S. Army Motion Picture Service. 

(5) Sound and Projection Equipment in War Department Theaters: by 
George L. Bub, Chief Sound Engineer, U. S. Army Motion Picture Service. 

(4) Administration of the U. S. Army Motion Picture Service: by R. B. 
Murray, Director. 

The U. S. Army Motion Picture Service, a self-supporting, non- 
profit making organization, operating directly under the Director, 
Special Service Division, Services of Supply, is concerned with all 
phases incident to establishing and operating War Department 
Theaters at United States Army posts, camps, and stations. 

To convey completely the various functions of this Service the 
symposium has been arranged, first, for the architect to cover the 
phase involving design, erection, and adaption of buildings to be 
known as War Department Theaters; second, for the mechanical 
engineer to cover the design, equipment, and systems of heating, 
ventilating, and air-conditioning these War Department Theaters; 
third, for the chief sound engineer to cover installing and maintaining 
sound and projection equipment in these theaters; and fourth, the 
director will cover regulations, policies, and administrative operations 
of the Service. 

3 



CONSTRUCTION OF WAR DEPARTMENT THEATERS 



CHARLES WELPLEY* 



This paper is divided into two parts : the first, covering the peace- 
time construction, growth, and design principles; the second, the 
wartime growth and basic governing principles, the latter period 
dating from the declaration by our President of a National Emer- 
gency on September 8, 1939. 

The peacetime history begins with the birth of the United States 
Army Motion Picture Service on January 1, 1921. At its inception 
the Service inherited a miscellaneous lot of buildings, including ser- 
vice clubs, mess halls, hangars, etc., whose only claim to the title 
"theater" was that they were officially so designated. It inherited 
also a handful of barn-like Liberty theaters built during World War I. 
The seats were anything that could be gathered up around the post, 
such as mess stools or benches. From then until 1926 the entire 
efforts of the Service of necessity were concentrated upon financial 
survival. With its head finally above water, it entered during 1926 
upon what may be termed its remodeling period. 

The first building to be remodeled was at Fort Sheridan, 111., fol- 
lowed in the same year by Fort F. E. Warren. The remodeling con- 
sisted mainly of the addition of a sloping floor and wall and ceiling 
coverings of some such material such as insulation board. Stringent 
economy in the expenditure of hard-earned money was the watchword 
of the day, exemplified by attractive indirect lighting fixtures con- 
structed from salvaged helmets and water-closet pull-chains. Fig. 1 
shows the Fort Bliss 82d Field Artillery Theater interior and is an 
example of the more elaborate interior treatment of those days. 
Fig. 2 shows an old wooden hangar which has been dressed up with a 
pagoda front porch. These and other projects of similar nature 
proved that efficient projection of an outstanding film produced 
maximum attendance only when the surroundings were attractive. 

* Architect, U. S. Army Motion Picture Service. 
4 



WAR DEPARTMENT THEATERS 



5 



The splendid financial result of this remodeling and improved 
operation enabled the Service to embark, in 1928, upon a limited 
theater construction program. These new buildings were the barest 
of brick shells (Fig. 3.). This stark simplicity was due to the fact 




FIG. 1. Interior stage view, Fort Bliss 82d Artillery. 








FIG. 2. Exterior, Kelly Field. 



that under the then interpretation of a certain statute no building 
costing more than $20,000 could be constructed on an army post 
without authorization from Congress even when the funds were not 
appropriated by Congress. 



C. WELPLEY 



[J. S. M. P. E. 



With the advent of sound it was necessary to correct acoustically 
many auditoriums that had been entirely adapted to silent pictures. 
Most of them were corrected by the use of insulation board, which 
then was more generally used for this purpose than it is now. In 



* f i' f 



%',' VVf 



1 1 * 
f 



FIG. 3. Interior rear view, Fort Moultrie. 




FIG. 4. Exterior, Fort Worden. 

1932 the Service fell heir to $640,000 of unappropriated funds of the 
War Department, which General MacArthur, then Chief of Staff, 
made available to this Service for theater construction. The plans 
of the buildings were prepared by the Office of the Quartermaster 
General, one seating 398 and the other 574. Fig. 4 shows the theater 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



at Fort Worden, Wash., the first of the smaller theaters to be com- 
pleted, and in Fig. 5 we have the one at Fort H. G. Wright, New 
York, the first of the larger. Fig. 6 is an interior stage view typical 




FIG 5. Exterior, Fort H. G. Wright. 




FIG. 6. Typical interior. 

of both these theaters. Thirty-one of these theaters were con- 
structed in less than 18 months, giving the Service a backlog of 
buildings designed for use as theaters and acoustically corrected. 
With the experience gained in the construction of these buildings, 



8 



C. WELPLEY [ J. S. M. P. E. 




FIG. 7. Interior stage view. 




FIG. 8. Interior stage view, after remodeling. 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



9 



work was begun on remodeling some of the earlier theaters. Fig. 7 
shows the Fort Myer theater before it was remodeled and Fig. 8, 
the appearance of the auditorium after its face had been lifted. In 




FIG. 9. Exterior, Fort Sam Houston. 







FIG. 10. Exterior, Fort Knox. 

1934 an approved opinion of The Judge Advocate General of the 
Army removed the $20,000 building restriction on unappropriated 
moneys. Thus the Service was enabled to plan theaters for some of 



10 



C. WELPLEY 



[J. S. M. P. E. 



the larger posts. No one could design and hope to build for $20,000 
a theater of the size and the interior finish required for Fort Sam 
Houston (Fig. 9) or for Fort Knox (Fig. 10). Fig. 11 is the theater at 
Hamilton Field, another type of building constructed at this time, 




FIG. 11. Exterior, Hamilton Field. 




FIG. 12. Exterior, Fort Benning; old theater. 

but only half the size of Fort Knox. These buildings were con- 
structed entirely from funds of this Service. 

During the Government "pump priming" period, funds from the 
Work Projects Administration were made available to the Service, 
to be expended principally for labor. The major portion of the 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



11 



supplies and materials were purchased from funds of this Service. 
At about this time the largest Army theater, built some years before 
at Fort Benning (Fig. 12) with troop labor, salvaged materials and 
some Service funds, was condemned by the structural engineers. 





FIG. 13. Exterior, Fort Benning; new theater. 




FIG. 14. Interior, Fort Benning; new theater. 

It was possible to replace this building only through the aid of WPA. 
Figs. 13 and 14 show the building that replaced the earlier one. 
Fig. 15 shows an adobe brick theater, a WPA project on the Texas 
border. Mexicans on relief made the adobe brick, In the short 



12 



C. WELPLEY 



[J. S. M. P. E. 



time between the opening of the Fort Barrancas Theater, late in 
1937, and the Fort D. A. Russell Theater in 1940, 17 theaters were 
completed. This was accomplished only by the use of standard 
plans. 

The theater construction problems of the Service are not stereo- 




FIG. 15. Exterior, Fort D. A. Russell. 




FIG. 16. Exterior, Fort B. Harrison; open-air theater. 

typed; at any moment the Service may be called upon to meet a 
special situation; for example, the addition of roofs to open-air 
theaters (Fig. 1 6) . This constitutes the reverse of the earlier Liberty 
theaters; the soldiers at Fort Sam Houston insisted they had the 
only existing open-air theater with a roof. Another instance was the 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



13 



placing of a tremendous 75-seat theater in a warehouse building at 
Nansemond Ordnance Depot in such a manner as not to interfere 
with a prized shuffleboard court. 

Fig. 17 shows how a portion of an old wartime hangar was con- 
verted into an attractive small auditorium seating approximately 300. 




FIG. 17. Interior, Chanute Field. 




FIG. 18. Interior, Selfridge Field. 

The Service has even built a theater in a boathouse (Fig. 18). The 
peculiar shape of the auditorium is the result of wrapping it around 
the boiler-room. The original building had two ceiling levels, which 
were so completely incorporated into the design as to give the ap- 
pearance that it had been consciously done to achieve the final effect. 



14 



C. WELPLEY 



[J. S. M. P. E. 




FIG. 19. Interior, Barksdale Field Gymnasium. 




FIG. 20. Interior, Barksdale Field Theater. 



At Barksdale Field this Service operated temporarily in the gym- 
nasium (Fig. 19). A little less than half of the building was con- 
verted into a modern air-conditioned theater. The Stadium type 
plan was used at Barksdale Field, La. (Fig. 20), to connect the main 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



15 



floor with the gymnasium balcony, the rail of which shows in the 
lower edge of the picture. 

At Fort Bragg and Fort Lewis the standard 574-seat theater was 
enlarged fifty per cent by knocking out the brick walls and build- 




FIG. 21. Big tent, 5th Division; Ft. Benning. 




FIG. 22. Interior, big tent; Camp Or d. 

ing a truss, using existing columns as part of the vertical members, 
then cutting the columns off and adding wings to each side of the 
auditorium. Temporary theater service frequently must be pro- 
vided. During maneuvers in the Carolinas open-air theaters were 



16 



C. WELPLEY 



[J. S. M. P. E. 




FIG. 23. Interior, Fort Sam Houston. 




FIG. 24. Lounge, Fort Sam Houston. 



constructed, using canvas side-walls of standard latrine screens to 
enclose the seating area. Standard Army Storage and pyramidal 
tents were used for projection rooms and offices. Screens were of 
plywood or tempered hardboard. 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



17 



During winter maneuvers in the south in 1939 the Service de- 
veloped, with the assistance of the U. S. Tent and Awning Company, 
a tent entirely suspended from outside masts (Figs. 21 and 22). 
They were constructed of black canvas to permit daytime showing 




FIG. 25. Foyer, Fort Sam Houston. 






m&^imfi 

FIG. 26. Interior, Fort Benning. 



of pictures, had 135 feet clear of all obstructions in the interior, and 
seated a little over 2000. 

The peacetime architectural problems and their effect upon the 
design of Army theaters differ somewhat from those of private in- 
dustry. The average peacetime Army post is a close-knit community 



18 



C. WELPLEY 



[J. S. M. P. E. 



consisting roughly of three groups of personnel : the officers, the non- 
commissioned officers, and the enlisted men. Wherever possible an 
attempt is made to place the War Department Theater within easy 




FIG. 27. Exterior TH-2 Theater, Langley Field. 




FIG. 28. Exterior, TH-3 Theater. 



access of these three groups. The enlisted men, of course, comprise 
the larger proportion of the post population as well as of the theater 
patronage; therefore, when compromise is necessary it is important 
that the theater be placed nearer to them. It is neither necessary 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



19 




FIG. 29. Interior, TH-3 Theater, without stage; Lowry Field. 




FIG. 30. Interior TH-3 Theater, with stage; Fort Bragg. 



nor desirable to provide conspicuous marquees, for everyone knows 
the location the the War Department Theater. 

The size of the theater is determined by the permanent population 
of the particular post. Usually seating capacity is based upon one 



20 C. WELPLEY [J. S. M. P. E. 

seat to every six officers and enlisted men. This is sufficient to serve 
the families of the officers and non-coms living on the post. Since 
it is impossible to foresee changes in post population, increases or 
reductions are taken care of by changes in the booking of films or in 
the number of performances per week. 

The unlimited ground area available for the site permits the use 
of standard plans of varying seating capacities. That is, a post of a 
given size can ordinarily be supplied with plans for a theater with 
approximately the proper proportion of seats to population without 




FIG. 31. Interior Lobby, TH-3 Theater; Lowry Field. 

overlapping lot lines and other restrictions encountered in the com- 
mercial field. The standard plans developed to date have seating 
capacities of 308, 422, and 900. The onset of the War cut short the 
development of plans for theaters of 200- and 600-seat capacities. 
This, it is believed, would have enabled the Service to meet the re- 
quirements of almost any Army post in the United States under 
peacetime conditions. Special plans are prepared for posts requiring 
more than 900 seats. Additional plans are always provided to adapt 
the standard plans to the individual site requirements, and the 
exterior design is varied to fit into the general local architectural 
scheme. 

Prior to December 15, 1941, the Office of the Quartermaster 



Jan., 1943] WAR DEPARTMENT THEATERS 21 

General was charged with the responsibility for the design and main- 
tenance of all construction on Army reservations. For this reason, 
the architect of the Army Motion Picture Service was stationed in 
the office of the Quartermaster General to assist in the preparation 
of plans. These buildings, erected on government reservations, are 
not subject to the jurisdiction of state or city building regulations. 
The Army maintains rigid control over the initial design of the build- 
ings. All architectural, structural, and mechanical plans and specifica- 
tions must be approved by the Army. Upon completion of the build- 
ing and before its acceptance by the government, the U. S. Army 
Construction Officer must determine whether the specifications and 
plans have been followed satisfactorily. 

The sale of tickets at a War Department Theater is not so simple a 
transaction as in the average commercial house. After chow the 
soldiers go over en masse for entrance to the first show. The com- 
bination of mass application, exchange of coupons for tickets, and 
cash sale of tickets and coupon books makes it necessary to provide 
twice as many ticket-selling facilities as the average commercial 
theater of comparable size. 

Constant consultation and reliance upon the recommendations of 
the Engineering and Maintenance Division of this Service, in the 
provision of projection and sound equipment, have kept the design 
of these theaters within the general recommendations of the SMPE. 
The width of image has been established as one-fifth of the viewing 
distance, which is slightly better than the average commercial size. 
None of the permanent theaters have used the reversed floor-slope 
plan, because in most cases some form of stage had to be provided 
for the use of local dramatic societies, or for lectures or other purposes. 
This made desirable the conventional floor slope. Better vision 
has been obtained, with exceptionally small losses in percentage of 
seats, by staggering the seats in the center bank. As the Service 
progressed from mess stools and benches to baseball stadium, to 
veneer chairs, to fully upholstered chairs, the conclusion has been 
reached that 34 inches center to center meets the average require- 
ments for the latter type of chair and the general use the soldier 
makes of the theater. All wiring diagrams are prepared by the 
Engineering and Maintenance Division to be incorporated into the 
working drawings for inclusion in the building. All space required 
by the projection equipment is checked by the Engineering and 
Maintenance Division. In line with the demands for general econ- 



22 C. WELPLEY [J. S. M. P. E. 

omy of construction acoustical material (Fig. 23) is limited to ma- 
terials whose finished surfaces are a definite part of the architectural 
treatment and at the same time provide the maximum units of 
absorption per dollar. These auditoriums are designed to have a 
period of reverberation, with one-third of the audience present, 
recommended by competent authorities. 

The initial development of new plans is closely correlated for 
heating, ventilating, and air-conditioning. This permits economy 
in the design of the distribution and recirculating system; also, 
many times essential parts of the ventilating system are incorporated 
as an integral part of the esthetic scheme of the auditorium. This 
close collaboration from the very inception of the plan has resulted 
in some of the most economical and efficient air-conditioning in this 
country. 

So much of the soldier's life is spent in barracks and in the bare 
rooms of the average Army buildings that it generally is a relief to 
him to get off the reservation where he can find some aspect of 
splendor and magnificence (Figs. 24, 25). While it can not, nor 
does it desire to, compete with civilian theaters in exuberance and 
rococo style the Service sincerely attempts to remove the soldier from 
the barracks atmosphere into something comparable with what he 
finds outside the Army. It has basically a standard plan, but in the 
furnishings,' such as theater chairs, stage settings, lounge furniture, 
and, in some rather rare instances, rugs, a general color scheme is 
evolved which embraces all these items, plus the painting of the 
building. Special lighting effects have been used to a limited 
degree in the auditorium (Fig. 26). The general practice of the 
Service is to have the house lights dimmed throughout the show, 
never relying entirely upon light reflected from the screen for general 
auditorium illumination during the picture. The lights found most 
effective for this purpose have been louvered reflectors flush with the 
ceiling, placed primarily over the principal aisles. 

About the middle of June, 1940, the Army began preparation of 
camps for the first peacetime compulsory military service in the his- 
tory of this country. This Service with its varied experience was 
able to step in and assist the Office of the Quartermaster General 
with the preparation of standard plans that would meet the require- 
ments of the new camps. In spite of the great pressure for the prep- 
aration of plans for all types of buildings and their construction, the 
first show was held in the small and large mobilization type theaters 



Jan., 1943] WAR DEPARTMENT THEATERS 23 

within six months after the first sketch was made. Camps varied 
greatly in size, and air fields were springing up all over the country. 
Capacities of the new theater buildings planned are approximately 
350, 600, and 1000 seats. Fig. 27 is the smallest. The 1000-seat 
theater (Fig. 28) was designed with the reverse-slope floor, in- 
tended only for motion picture entertainment (Fig. 29). This was 
in the beginning, before the demand for flesh-and-blood shows. 
Later an alternate plan was developed with conventional floor slope 
and a stage (Fig. 30). Fig. 31 shows a lobby in one of the 1000- 
seat theaters that has been furnished and dressed up. 

These buildings have the same spacing of seats and relation of 
image size to viewing distance as the best of the standard theaters of 
the Service. Because of the temporary nature of the buildings 
theater seating was not used. The seats are wood benches built by 
the contractor (Fig. 30). The buildings are constructed entirely of 
wood, except for the concrete foundation walls and concrete first floor 
slabs. Wherever possible standard lengths of wood were used for 
wall studs, ceiling, and roof joists. 

On December 15, 1941, the Office of the Chief of Engineers, by Act 
of Congress, took over full responsibility for all Army construction. 
This Service has the same close relations with the Design Section 
of the Office of the Chief of Engineers as it had previously with the 
Office of the Quartermaster General. 

Many of these three types of buildings have been constructed, but 
following Pearl Harbor and the increased consumption of steel and 
other metals to supply our fighting machines, it was necessary to 
review these plans with the object of reducing to an absolute mini- 
mum the quantity of critical materials that go into them. Not only 
metal, but lumber also must be used as sparingly as possible. Two 
theater buildings seating 500 and 1000 have been developed reducing 
the row spacing and the aisle space in the auditorium to an absolute 
minimum. Also, the ratio of the screen to the viewing distance was 
reduced to approximately 1:6, which permits lowering the audi- 
torium and decreasing the space from the front row of seats to the 
screen. All the spaces normally required by the Army Motion 
Picture Service for this building to function as a War Department 
Theater were simplified and cut to the bone, for these buildings are 
being constructed now primarily to provide a means of training our 
men in the methods of war, and only secondarily to provide recrea- 
tion. 



HEATING, VENTILATING AND AIR-CONDITIONING WAR 
DEPARTMENT THEATERS 



M. D. KICZALES* 

The furnishing and installation of air-conditioning in War Depart- 
ment theaters during the peacetime growth of the Service developed 
in step with progress in other directions. The buildings that the Ser- 
vice inherited were equipped with heating systems of the "gay-90's" 
design which usually caused overheating by a super-abundance of 
cast-iron radiators without benefit of any ventilation whatsoever. 
The auditoriums were well supplied with oscillating fans for summer 
operation, but their use died when sound pictures were born. 

To substitute for the multiplicity of droning propeller-blade fans, 
and selected by foresighted marketing very much limited by avail- 
able funds, multiblade blowers were installed on each side of the 
proscenium opening (Fig. 1). Even though air- tempering was known 
to be very desirable, these blower systems were not so provided and 
were, of course, thereby limited to summertime use only. 

As the novelty and newness of sound pictures wore off, patrons 
began seeking perfection. To meet the demand, architectural im- 
provements were made in auditoriums, and the designs of the 398- 
and 574-seat standard-type theaters included improvements in the 
so-called air-conditioning systems wherein the same type of blower 
system was used but with many additions. 

Limitation of funds required that greatest utility be obtained 
with the least expenditure of money. The specifications and de- 
sign of these standard theaters set maximum air velocities to a safe, 
noiseless level and provided for the tempering and reheating of air for 
winter operation. With manually operated dampers the blowers 
provided 30 cfm of air per seat for winter operation with approxi- 
mately one-half outside air, and 60 cfm per seat of all outside air for 
summer operation. 

The Fort Sam Houston, Texas, theater was the first to be provided 
with complete automatic air-conditioning. All the cooling equip- 

* Mechanical Engineer, U. S. Army Motion Picture Service. 
24 



WAR DEPARTMENT THEATERS 25 

ment was installed by a contractor who was awarded the contract 
after formal sealed bids were submitted on the basis of plans and 
specifications prepared by the Service. The Fort Riley theater, 
originally provided only with heating and ventilating equipment, 
with manual dampers and proscenium air-supply grilles, was next 
remodeled to include air cooling. The proscenium grilles were re- 
placed by air-supply grilles longitudinally placed at the ceiling of the 
auditorium. This cooling work was done also on a bid-awarded con- 
tract basis. The cost of the cooling work alone for both these theaters 
was from $20 to $22 per seat, and in each case constant inspection 




FIG. 1. Proscenium grille blower system. 

was necessary and continuous wrangling ensued to secure compliance 
with the plans and specifications. 

When the first cooling system was installed it was planned to 
provide all the permanent theaters of the 398- and 574-seat type with 
cooling. The high cost per seat of contract work drastically limited 
the number of theaters that could be so provided. It was therefore 
decided to attempt a remodeling for cooling installation on a pur- 
chase-and-hire basis. The design engineer was then appointed 
supervising engineer in charge of installation, and the Fort Meade, 
Md., theater, a 574-seater, was selected for the experiment. Plans 
were quickly drawn up, equipment purchased on a bid-awarded basis, 
and a foreman hired to direct the working crew. The design engi- 
neer and the supervising engineer being one and the same, operated 



26 



M. D. KlCZALES 



[J. S. M. P. E. 



between his office in Washington and his experiment at Fort Meade. 
All necessary materials such as copper pipe, fittings, sheet metal, 
cork, and so forth were purchased and the necessary labor hired. 
The proscenium grilles were removed and the ducts supplying the 
grilles were run up into the attic space, joined into one, and con- 
tinued to the rear auditorium to two specially designed grilles in- 
jecting air into the auditorium toward the stage and recirculating 
it at the floor of the rear wall. The net results of this experiment 
were manifold : 





FIG. 2. Fan and air plenums 900-seat theater. 



(1) The final cost for this cooling system provided with complete 
automatic controls, dampers, and the best material and workmanship 
available, amounted to $13.28 per seat. 

(2) By keeping careful accounts, the costs of the various com- 
plementary parts of the system became known and were used for 
study in reducing costs of future designs. 

(3) By the use of specially designed dampering devices and duct 
designs, in an empty auditorium with the blower and refrigerating 
units operating simultaneously, the noise level was reduced almost to 
inaudibility. 

(4) Two new automatic features were tested which were in- 
cluded in all later designs. During winter operation, a fixed mini- 



Jan., 1943] WAR DEPARTMENT THEATERS 27 

mum outside-air volume was mixed with recirculated air, this mini- 
mum being maintained for a design winter outdoor temperature and 
an automatically increasing amount of outside air from minimum 
quantity to full blower capacity, proportioned over the temperature 
range from design minimum to 63F, with a simultaneously pro- 
portioned reduction in the recirculated to zero quantity. If the 
outside temperature rose above 63 F and the audience load produced 
high inside conditions, a flip of a switch put the cooling system into 
operation. 

The inside maintained temperature was controlled automatically 
by the outdoor temperature; when the outdoor temperature was 




FIG. 3. Refrigerating condensing units 900-seat theater. 

75 F the indoor temperatuie was maintained at 75F, and for each 
4F rise of outside temperature the inside temperature was automat- 
ically increased one degree and vice versa. 

With the lessons learned by this experiment, the air-conditioning 
designs were then prepared for the 900- and 422-seat theaters. All 
the cooling .installations in these theaters were done under the 
direction of the designing-supervising engineer who then led a Dr. 
Jekyl and Mr. Hyde existence; finding the faults of his designs during 
his field work and striving to improve his design so that he could 
not find any faults with himself in the field. With a trained crew 
of installation foremen, and operating along lines followed during the 
experiment, the cooling costs were reduced to $9.07 per seat. 



28 M. D. KICZALES [J. S. M. P. E. 

The design of the 900- and 422-seat theaters constructed during 
the WPA era included complete all-around air-conditioning; that 
is, heating, cooling, ventilation, humidity control, and air filtering 
with engineered air distribution. These systems are completely 
automatic, and all operation is controlled by the fan push-button in 
the manager's office. Whereas the basic design and air distribution 
were standard, the complementary parts were varied in accordance 
with local conditions. Boilers were specified for the types of fuel 
available, with the cooling equipment dependent upon availability 
of condensing water, well water, and outside temperature and 
humidity conditions. When it was determined in what locality one 
of these theaters was to be built, a special plan and specifications 




FIG. 4. Supply duct and branches installed at ceiling 900-seat theater. 

were drawn up for the heating and cooling equipment to meet local 
conditions after careful consideration and study of comparative 
initial costs and operating expenses. It would take many hours to 
describe how these studies were made and the final selections arrived 
at, but a brief description of a few of the installations showing such 
variety may prove interesting. 

At Fort Snelling, an abandoned well, about 500 feet back of the 
theater, showed by tests during the month of August to be flowing 
425 gpm of 42F water. The well was capped, a pump installed 
next to it, and 250 gpm of this water were automatically pumped 
through cooling coils at the theater and found to be more than ample 
for all peak loads of audience and for outside dry- and wet-bulb tern- 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



29 



peratures. This was a modernization installation replacing a pro- 
scenium-grille blower system. A little of the savings in costs of the 
electric refrigeration was diverted to the air distribution ; ceiling type 
anemostats were installed and tested and were incorporated in future 
designs. 

At Fort Moultrie, S. C., available water for condensing purposes 
ran as high as 105F during the summer and to meet this situation 
an evaporative condenser was used. 

At Fort Benning, Ga., the largest installation of Freon water coolers 




FIG. 5. Architectural treatment, supply duct and grilles 900-seat theater. 



in the country at that time was made. One hundred and thirty 
horsepower of electric refrigeration, consisting of two 40-hp and two 
25-hp refrigeration condensing units connected to their respective 
water coolers, were so controlled that the cold water pumped to the 
air-cooling coils was kept to within 1F of the designed water-cooling 
temperature. By the use of automatic modulating dampers, the 
inside temperature was maintained to within 1F, as set by the out- 
side temperature controller. The complete system is so flexible that 
any sudden changes in audience load are met quickly, as was indi- 
cated by the smooth curves obtained on many charts made by using 



30 M. D. KICZALES [J. S. M. P. E. 

five individual temperature-humidity recorders simultaneously, 
placed at different points on successive nights of a one-week test. 

All the air-conditioning systems were so controlled as to be as 
foolproof as possible without requiring any men to observe the 
machines in operation. Warning signals were incorporated in the 
control systems to indicate improper operation of any one part of the 
equipment, and proper cutouts were included to prevent continued 
faulty operation. 

Briefly described, in the 900-seat theater, all machines including 
the boiler (Figs. 2 and 3) are installed in an annex built at the rear 
of the building separated from the stage by a solid brick wall and 




FIG. 6. Rear wall supply and recirculating grilles 422-seat theater. 

the air-supply ducts enter the auditorium under the stage (Fig. 4), 
rising up to and running along the length of the auditorium ceiling. 
This duct is architecturally treated (Fig. 5) and the specially de- 
signed grilles inject the air into the auditorium from both sides of 
the duct. The air is exhausted or recirculated through grilles under 
the stadium seats, in the cross-walk partition and side-walls. The 
portion of ah- to be completely exhausted from the building for 
replacement by outside air is first used to semi-cool the lounges and 
toilet rooms built under the stadium seating area, and then after 
being blown through the attic space above the auditorium ceiling is 
allowed to exhaust to the outside. 

The Service is quite proud of the design of the air-conditioning 
system of its 422-seat theater. The proportions of the auditorium 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



31 



indicated immediately that a rear-wall grille supply as was used 
in the Fort Meade experiment would fit exactly (Fig. 6). To 
eliminate the duct from the stage end to the rear auditorium, it 
was decided to move all the equipment, blower, coils, filters, and 
refrigerating units to the projection-room end of the theater. In the 
attic space above the projection room, the supply blower, coil, and 
filter banks were placed with fresh-air intakes and recirculating ducts 
(Fig. 7); a room adjoining the projection room was used for the 
refrigerating condensing units. The amount of duct work was cut 




FIG. 7. 



Diagram showing compactness of complete air-conditioning system 
422-seat theater. 



to an irreducible minimum and with special connectors, machine 
bases, and acoustical treatment, no mechanical or air-borne noises 
are heard in the seating area (Figs. 8 and 9). The results were most 
gratifying. 

As the work progressed in the WPA-Motion Picture Service- 
sponsored theaters, attention was again turned to the 398- and 574- 
seat houses. The Fort Meade and 422-seat theaters proved that 
the modernization costs could be reduced if the long duct run from 
stage to the rear wall could be eliminated. Again it was decided to 
experiment. Another theater exactly like Fort Meade's 574-seater 



32 



M. D. KlCZALES 



[J. S. M. P. E. 



was used, and this time the two proscenium grilles were removed and 
plates having three wall-type anemostats in each were inserted in 
place. Being somewhat dubious as to the results, the supply ducts 
were continued up through the attic to connect to six small ceiling- 
type anemostats. However, these ducts to the ceiling outlets were 
provided with shut-off dampers to enable testing with all the air 
being supplied from the wall-type plates. It was found that when 
using the wall plates only, the temperature throughout the seating 
area during the cooling operation varied only within one degree, and 
in no seat were there any drafts. 




FIG. 8. Refrigerating units on isolating bases 422-seat theater. 

With this last experiment, the irreducible cost and most efficient 
and expedient remodeling and modernization design were arrived 
at, and then came the war emergency which stopped all air-condition- 
ing work. 

When the large 2000-seat tent theaters were developed and erected 
by this Service in 1939, for use during maneuvers, the need for heating 
presented a real problem. It was solved by a "Rube Goldberg" 
invention costing $20 and consisting of coke-fired salamanders, 
which were fired outside the tent. After smoking themselves out, 
each was carried into the tent and placed in strategic positions in the 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



33 



aisles with guard-rails around them. For temporary use, these 
salamanders produced the desired results, as a system was set up 
for firing and placement indoors in accordance with outside tem- 
perature and audience. Eight salamanders, at a cost of $2.50 each, 
operated on a relay system, produced inside temperatures of 68 with 
outside temperatures as low as 21. By the use of an Army pyra- 
midal tent, one coke-fired salamander, and two "guinea pigs" in the 
persons of the director of the Service and the surgeon of the 5th 
Division, it was determined that no dangerous fumes were present 
after the smoking-out process ceased. The results of this experiment 
were later confirmed by conventional testing methods. When the 
War Department authorized the construction of over twenty tent 
theaters of the same type, mobile oil-fired heating units having blower, 




FIG. 9. Water circulating pump on special noise insulating 
base 422-seat theater. 

burner, oil storage tank, outside and recirculating grilles, all set up 
as one complete unit on skids, were designed by the Service and pro- 
vided by the Government for each tent theater. 

The mobilization-type theaters now in operation at Army posts 
are provided with heating and ventilating systems designed basically 
on the systems provided in the newer permanent theaters with no 
cooling equipment installed, but with provisions in the design that 
permit simple and easy installation of cooling coils and refrigerating 
condensing units at any time in the future, without requiring any 
changes in the present system. In the meantime the ample pro- 



34 M. D. KICZALES 

visions for outside air for summer operation have proved adequate 
and conditions not so uncomfortable. 

Due to conditions concerning critical materials, redesign of the 
mobilization-type theaters was necessary and the Service was called 
upon to advise and make recommendations for the design of the 
heating and ventilating system. With its background of experi- 
ments in designs, tests, costs, operating efficiencies, and satisfactory 
results, the Service was able to survey quickly the new building de- 
sign and recommend the most efficient heating and ventilating sys- 
tems requiring an irreducible minimum of essential critical materials. 
These recommendations have been accepted and incorporated in 
these new theater designs. 



SOUND AND PROJECTION EQUIPMENT IN WAR DEPART- 
MENT THEATERS 



GEORGE L. BUB* 

This engineering phase of the U. S. Army Motion Picture Service 
includes first, the equipment; second, installation; and third, main- 
tenance. 

The first War Department Theaters taken over by the Service for 
the most part contained only 'one projector. Those having two 
projectors in many cases had two different makes. Such equipment 
consisted of Simplex front shutter, Motiograph 1A table type, and 
Powers 6 A and 6B projectors; incandescent a-c and d-c arc lamps; 
transformer, tube rectifier, and gasoline-electric generator power 
supplies; and from muslin to white plaster wall screens. 

The first equipment problem of the Service was to provide each 
projection room with two projectors of the same make. The aban- 
donment of camps during the demobilization period following World 
War I created a sufficient surplus of equipment to enable solving this 
problem. It was necessary to establish a common storage point to 
which equipment could be shipped for inspection and repair where 
possible; therefore, the end section of a warehouse at Fort Sam 
Houston, Texas, was secured for this purpose. This storage space 
became the first National Repair Shop of the Service. The work of 
repairing and selecting the best of the equipment and of installing it 
in the theaters to be operated was completed in 1922. The first 
stock of parts resulted from the surplus of this equipment. 

Following the solving of the first problem came the urge to im- 
prove. Being constantly confronted with a condition of extremely 
limited finances developed in the engineering staff a spirit of in- 
genious resourcefulness, which led to the highly gratifying result of 
several of creditable "firsts." 

The first satisfactory projection by incandescent lamps on a screen 
of a size requiring a then modern arc lamp was accomplished in 1923. 

This improvement was effected by matching more closely the 

* Chief Sound Engineer, U. S. Army Motion Picture Service. 

35 



36 G. L. BUB [J. S. M. P. E. 

speeds of the light-source and projection lens as described by Roger 
M. Hill (Trans. Mot. Pict. Eng., No. 20 (Sept., 1924), p. 82). The 
first rear-shutter projector was developed as a by-product and placed 
in use in 1923. The first turntable enabling emphasis of the moods 
of pictures with appropriate recorded music was placed in use at 
Fort Warren in December, 1926. The influencing factor here was 
the inability to provide conventional orchestral accompaniment. 
The Service was the first to purchase rather than lease sound-re- 
producing equipment; the first to use its own employees to install 
and to service such equipment. The first open-air theater projecting 
sound-motion pictures was placed in operation in 1930 at Fort Mc- 
Clellan, Ala, 

The experience gained by installing and maintaining its own 
equipment caused the Service to embark upon a period of equipment 
modifications. The purpose here was twofold : simplifying servicing 
and improving operation. Thus the time spent by engineers on 
servicing was reduced as was the frequency of regular servicing visits, 
and there was a material lessening in emergency calls. Over a period 
of time the results in this connection were that the Service was able 
gradually to decrease the number of servicings per theater from 12 
to 4 per year. The decrease in time required of the engineers on 
servicing increased the time engineers had available for repair work 
and equipment development at the National Repair Shop, since 
renamed the Engineering and Maintenance Division. This became 
an opportunity for the engineers to compare their experiences on 
difficulties encountered and solutions found in servicing work. The 
advantages gained thereby were not only the broadening and the 
developing of the engineers' analytical ability, but also many im- 
provements and modifications to equipment essential to efficient 
operation. 

The extent of this modification work, necessitating the compilation 
of a fifty-page catalog for use by our field engineers, makes it obvious 
that it would be impracticable to go into detail here; however, to 
illustrate, when tests disclosed the fact that arc motor-generator sets 
provided sufficient voltage for dynamic loud speaker fields normally 
excited by a 110- volt d-c rectifier unit, an emergency switch was 
provided for use when such a unit failed. 

Oil-soaked cables were removed from the bottoms of units of the 
sound motor-generator set, and replaced with leads brought out 
through the tops of the end bells of the units. Control panels of 



Jan., 1943] WAR DEPARTMENT THEATERS 37 

these motor-generator sets were removed, and revamped units and 
circuits were incorporated in a wall-mounted panel. Amplifiers 
were not only rewired but the circuits revised to improve the gain 
and response and to include characteristic-warping networks and 
filters. 

Rear-shutter shafts were cut flush with shutter hubs and a lock- 
plate provided to hold the shutter in time. The lower pins in the 
rear-shutter housing brackets were locked into the mechanism case 
to prevent loosening and causing binding in the end bearing of the 
shutter shaft. Magazine hinges were modified to hold the door in a 
fixed open position to facilitate threading film. An automatic fire- 
shutter lift-lever was designed and installed on projector mechanisms 
to lift the fire shutter automatically when the film-trap door was 
opened. 

A USAMPS douser was designed and used on rear-shutter and 
Super projectors for the purpose of providing an arc beam cut-off 
blade in the rear shutter housing to protect the shutter (Fig. 1). 
Projection-lens focusing devices and also rear-shutter timing devices 
having control knobs accessible in the front covers of projector 
mechanisms were developed and used. These illustrations cover 
the representative fields of endeavor from electronics to machine 
design. 

With the installation of sound equipment, War Department 
theaters for the first time were able to offer entertainment equivalent 
to that provided by civilian houses. Improvements in the method of 
servicing effected by these modifications, according to reports from 
the majority of posts, created somewhat of an edge in favor of War 
Department theaters over many civilian houses. New patronage 
was created in the persons of Army officers and their families, and 
the attendance of enlisted men steadily increased, with the result 
that the financial status of the Service very shortly was such as to 
permit purchase and installation of the latest types of sound and pro- 
jection equipment available. 

From that time on, the Service has been keeping abreast of de- 
velopments in sound reproduction and motion picture projection, 
using as guides the recommendations of the Academy of Motion 
Picture Arts & Sciences and of the Society of Motion Picture Engi- 
neers. This information and the unique experience of the Service 
have formed the basis of standards of equipment, of installation, and 
of maintenance in practice in War Department theaters today. Thus 



38 G. L. BUB [J. S. M. P. E. 

sound and projection equipment is selected not only for the given 
type and size of theater but also for its operation and location. To 
meet the wide range of requirements of the many types and sizes of 
War Department theaters, the Service uses projectors from portable 
to E-7 types; light-sources from 900-watt incandescent lamps to 
125-ampere Suprex types; power-supply units from transformers and 
tube rectifiers to large motor-generator sets; sound equipment from 
5 watts to 60 watts; screens from 8 feet wide to 27 feet wide. Very 
often it is necessary to use heavier-duty equipment in smaller theaters 
where both training film and regular motion picture performances are 
projected throughout every day of the week. In the most isolated 
locations it is essential, in order to insure continuous operation, to 
provide stand-by equipment and supplies. The Service must also 
be prepared to meet not only emergency installations miles from a 
power line but also situations where either the number of men served 
or the operation schedules change. In the performance of its mission, 
the Service found how prophetic were the Chief of Staff's instructions 
to the Army to the effect that "We must be prepared to operate in 
the Arctic or in the tropics, in deserts or in mountains . . . ," for 
motion picture installations have been required in all four of these 
areas. Due to the difficulties attendant upon meeting some of these 
situations the Service has upon occasions been required to com- 
promise its standards. 

Having established standards as to types of equipment to be in- 
stalled in various theaters, the next problem was to coordinate the 
building completion date and the arrival of equipment, of the in- 
stallation engineer, and of the film program, so as to open the theater 
on a predetermined date. The building completion date is, of course, 
not within the control of the Service. Many an engineer and film 
program went on a wild-goose trip until post commanders found from 
experience that the Service is geared up to supply an engineer on the 
exact date the building is to be completed, to have all equipment on 
hand prior thereto, and to commence service on a fixed date. In this 
connection perhaps the most interesting phase is the time allotted 
engineers to complete installations. Engineers are scheduled to 
complete installations of the smaller type of equipment in 2 or 3 
days, the intermediate types in 3 to 5 days, and the larger types in 
5 to 7 days. These periods include the necessary paper detail work. 
Whereas local conditions have extended these periods in some few 
cases, installations have been completed ahead of schedule in others. 



Jan., 1943] WAR DEPARTMENT THEATERS 39 

For example, smaller equipments arriving around noon have been 
placed in operation the same night, and the largest equipments were 
in operation on the third night following the arrival of the engineer. 

Every possible effort is extended to facilitate the installation work. 
To this end detailed plans are furnished, in which are included 
methods established on the basis of experience and of conclusions 
relative thereto which were reached at annual conventions of the 
engineering staff. These plans require all wiring to projectors to be 
brought up through the projector bases. This wiring includes not 
only circuits to projector motors, arc lamps, pilot, and framing lights, 




FIG. 1. USAMPS douser. 

but also douser wiring, exciter-lamp circuits, and sound-polarizing 
and signal circuits. This plan involves drilling holes in the projector 
bases to permit continuing the circuits through greenfield to individual 
units of equipment mounted on the bases. To facilitate checking of 
circuits the wiring is so arranged that no splices appear in floor boxes, 
all wires ending at a terminal strip. Sound- wiring plans indicate 
belden-shielded, cambric-insulated, and stranded wires where previ- 
ous tests and usage indicated their advantages. Thus the difficulties 
peculiar to lead-shielded, rubber-insulated and solid conductors in 
these circuits are avoided. All conduit, wire, and junction boxes, as 
well as the location and size of the various units of equipment fur- 
nished by the Service, are shown on these plans. Despite all these 



40 



G. L. BUB 



[J. S. M. P. E. 



precautions plans are sometimes misinterpreted to the extent that 
engineers find projection rooms in various stages of completion and 
conformity with plans from no conduit to beautifully completed jobs. 
For example, sound circuits have been found terminated in power 
panels, sound-head junction boxes have been located near the ceiling, 
arc-lamp runs appeared in the ceiling instead of the floor, a few of the 
runs were dead-ended, I 1 /2-inch conduit became 1 / 2 -inch. Probably 
the most serious error was that where, because of the location of water 
and sewer lines, it became more advantageous from the contractor's 
viewpoint to reverse the original plant to shorten the plumbing lines 
to the washrooms. The contractor, carrying through on the reversal, 




FIG. 2. Screen installation with black-printed plywood screen border. 



obligingly located the ports, wall, and floor boxes to operate the equip- 
ment from the wrong side. The engineer lost eleven pounds on this 
installation but opened on schedule. In the belief that the method 
of indicating electrical work in the usual conventional manner might 
be responsible for such misinterpretations, a simpler layout plan, 
showing all four walls and the floor so arranged as to indicate entire 
conduit runs from start to end, was developed. Recent indications 
are that the new plan is accomplishing the desired results. 

Having solved this projection-room problem, the engineer proceeds 
to examine, repair if necessary, and to test individual units. All 
equipment grounds made at the factory are examined, and in many 
cases it is found necessary to scrape paint from or to tin the connecting 
parts. It has been necessary in some instances to extend the shield- 



Jan., 1943] WAR DEPARTMENT THEATERS 41 

ing nearer to the lead terminals. During assembly and wiring of 
equipment arrangements are made to have the assigned projectionists 
on hand not only to assist but to be instructed with regard to the 
equipment, its operation, and its maintenance. 

In order to expedite his work the engineer is provided with an 
installation kit which has been developed for the particular type of 
equipment being installed. This kit includes special wire, con- 




FIG. 3. Warble oscillator. 

nectors, terminal strips, and other items not usually supplied by con- 
tractors to permit planned completion. 

When the projection room installation is well under way the engi- 
neer's next problem is on the stage with the screen, the plans indi- 
cating whether it is to be stationary or movable. The stationary 
types are readily mounted to the back wall or suspended on cables, 
but the movable types are either hinged to a low ceiling, mounted on 
tracks or swung on angle-iron brackets up and against the back wall. 
In the latter method the engineer may find conditions where last- 
minute changes are made in the building structure or in locating heat- 
ing and ventilating ducts that require corresponding changes in the 



42 G. L. BUB [J. S. M. P. E. 

details of installing the screen rigging. His main concern, of course, 
is maximum protection of the screen. However, before installation 
of the plywood screen border, which is painted to harmonize with the 
stage except for a black border approximately 3 per cent of the 
width of the screen (Fig. 2), the projection optical system is aligned 
so that the centers of the carbon, aperture, and projection lens form 
a straight line. A pinhole aperture plate is used to adjust the light 
distribution over .the surface of the screen. 

The stage loud speaker assembly, with which the engineer is next 
concerned, may be located in a built-in compartment, mounted on a 
stationary or roller platform, or mounted to a movable screen as- 
sembly. With respect to the wiring connections the engineer usually 
makes these himself, to be certain of phase and polarity relations, 
since colored wire schemes are not assumed to be correct. Here 
again he is assisted with cables, terminal strips, plugs, and receptacles 
from the special installation kit. 

With the stage equipment work planned and under way, his 
attention is then given to the auditorium seating, which may be 
either regular theater chairs or wood benches. When regular chairs 
are to be installed he is usually called on to supervise the work. In 
such cases plans provide not only a detailed arrangement but methods 
by which the floor layout may be expedited. These methods include 
not only the location of the center of the arc of the front row of seats, 
which lies outside the rear stage wall, but also a simple method of 
transferring this arc to its proper position. A large T-square is made 
up to locate four row arcs at a time, and templates for each of the 
various widths of seats are used to spot positions of seat standards. 
For this work the installation kit provides electric hammers, drill 
points, and double-shielded anchor bolts with locking nuts. The 
organization of the balance of the work follows the usual conventional 
method. 

The next and probably the most important consideration on an 
installation is to secure the desired acoustical sound reproduction. 
Designed acoustical correction often falls short of theoretical ex- 
pectancy due to variations in compliance with specified methods of 
installing different acceptable acoustical materials. Acoustic quali- 
ties of newly designed theater auditoriums are always questioned. 
The acoustical characteristics of several of the various types of 
theaters were surveyed by the use of a warble film and a sound-level 
meter. These tests established the fact that data so obtained were 



Jan., 1943] WAR DEPARTMENT THEATERS 43 

subject to serious inaccuracies, largely due to the limited number of 
recorded frequencies at which readings could be taken. To secure 
the desired accuracy required to determine and correct certain ob- 
served conditions in auditoriums, a warble oscillator was developed 
(Fig. 3). 

This oscillator made possible the introduction into the sound- 
system amplifiers of a warble tone, continuously variable over the 
entire frequency range. The warble was produced by a motor-driven 
condenser, the capacity of which was made to vary by means of a 
mechanical linkage in such manner as to maintain the width of the 
band of frequency modulation at a constant percentage of the funda- 
mental, or midpoint, frequency. This was shown to be necessary 
if the same degree of accuracy was to be obtained in measurements at 
high and low frequencies. Three widths of warble bands were made 
available by adjustment of the linkage, making it possible to explore 
any band of frequencies very accurately, or less accurately but in 
a shorter time by averaging the outputs over wider warble bands. 

By use of this device acoustical characteristics could be taken in far 
less time than was previously the case with film. It is interesting to 
note that film tests often showed much greater differences in sound 
quality from point to point in an auditorium than listening tests 
indicated, while the oscillator usually showed differences of the 
order of those that the ear indicated as probable. While tests made 
with this instrument were very useful in determining the general 
nature of certain acoustical conditions and auditory effects, especially 
in the region below 1000 cps, the time required to make a complete 
analysis of an auditorium made general use of the instrument im- 
practicable. However, much that was learned by these tests is 
utilized in routine adjustments today. In order to equip the engineer 
with a means of achieving the desired acoustical response, he is given 
information by which sound characteristics may be recognized and 
described. For each of the various characteristics of sound a chart 
provides a range of frequencies producing the characteristic and a 
series of mathematically derived and tested curves identified with 
the constants in a given circuit. Therefore, on an installation in a 
theater, the auditorium of which appears to have the specified 
acoustical correction, the engineer proceeds with the installation on 
the basis that the acoustical properties are approximately correct. 
The amplifier is first checked and a characteristic curve taken with 
the calibrated frequency test-film and a meter across the correct 



44 G. L. BUB [J. S. M. P. E. 

loading resistor connected at the amplifier output terminals. The 
warping network is adjusted to the characteristic recommended by 
the Engineering and Maintenance Division. After a test run with 
the equipment properly connected and adjusted, the engineer sends 
with his report the characteristic curve together with his remarks as 
to quality of sound, connections made, and gain setting. Since the 
former tests were made in an empty auditorium, remarks are also 
supplied regarding the program, sound quality, and estimated at- 
tendance during a regular performance. In this manner the Engi- 
neering and Maintenance Division is provided with information by 
which a determination may be made on subsequent visits to the 
theater as to whether circuit constants or gain have changed or 
whether adjustments have been made. Of course, such work is more 
complex than indicated, as equipment does not always arrive in 
correct operating condition and defects do not always show up on 
preliminary tests. For example, in one case where an unsuitable 
amplifier-film characteristic resulted from incorrect rotational ad- 
justment of the optical system, it was necessary to provide an eccen- 
tric adjusting and clamping piece to replace the machined block 
designed to hold the optical barrel in correct rotational position. 

On almost every installation the varied local conditions create 
problems in the shielding of signal circuits and the locating and 
connecting of effective ground wires. Especially on installations 
of the high-impedance input types of sound equipment, corrections 
to circuits become necessary because of interference pick-up of range- 
finder signals as well as of various circuit-breaking equipment. 
Generally the solutions to such types of interference are found in the 
use of radio-frequency chokes and condensers located either at the 
point of pick-up in the signal circuit or by connecting a condenser 
across the contacts as close to the offending circuit-breaking points 
as possible. The usual solutions to grounding problems are found 
to be first in the use of independent ground wires for equipment and 
signal circuits, as well as in securely bonding continuous shields at 
only one point to avoid ground-loop currents when two grounds 
are at different potentials. Engineers are usually aware that various 
grounds have various potentials, depending upon the size and length 
of the grounding wire, the resistance of points in conduits and water- 
pipe, type of soil, dampness and acidity, and depth of grounding coil 
or length of ground rod. In other cases excessive hum was traced 



Jan., 1943] WAR DEPARTMENT THEATERS 45 

to a clearance space in the exciter-lamp partition, which permitted a 
small beam of reflected light to project through the sprocket-holes of 
the film onto the photocell. With the possible exception of a few 
refinements, the remainder of the installation proceeds in the usual 
manner. 

In addition to initial equipment installations there is also the later 
necessity of replacing a portion of all sound and projection equip- 
ment in a theater already in operation. An interesting feature of this 
type of work is the continuance of regular performances during the 




FIG. 4. Projection room instruction rack at the E. & M. Division. 

change-over. The usual "if -possible" method of procedure is to 
clear conduits of all wire not to be used for the new equipment, re- 
locate the original equipment so as not to interfere with the new 
equipment locations, and reconnect the old equipment in a "hay- 
wire" fashion. Certain units of new equipment may be used in con- 
junction with units of equipment to be replaced. In one case this 
work involved moving the front wall of the projection room 3 feet 
forward on a balcony. The new front wall was erected but with large 
openings permitting projection from the original position of the pro- 
jectors. The engineer and projectionists were required to project 
each performance not only with different combinations of equipment, 



46 



G. L. BUB 



[J. S. M. P. E. 



but also by means of different controls in different locations. The 
audience could not appreciate this, of course, since they were kept 
in the dark. 

On other occasions equipment is transferred from indoor to outdoor 
theaters and vice versa, without interfering with continuous perform- 
ances. In one instance the scheduled matinee performance in a new 
theater was projected with equipment used the night before in the 




FIG. 5. Fire shutter. 



old theater. A considerable amount of manipulation was necessary 
to transfer the equipment and wire it to meet the schedule, but it 
was done. 

Installations made prior to the present emergency were scheduled 
as a portion of a servicing loop; however, the servicing loops now 
are smaller and are scheduled between installations. Nevertheless 
the frequency of servicing visits to a theater has been changed from 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



47 



four to six per year because of the extraordinary turnover of pro- 
jectionists necessitated by military transfers. 

Servicing visits were formerly planned in clockwise loops from St. 
Louis in order to cover a maximum number of theaters with a mini- 
mum* of time and miles traveled. Engineers started on these loops 
in rotation at intervals of two weeks. The purpose of this plan to 
distribute engineers throughout the states is now generously pro- 
vided for by the many and scattered installations. Every advantage 
must be taken of an engineer's availability between installations in 




FIG. 6. Projector fusejblock. 

order to maintain scheduled servicings. An engineer is usually 
allowed one day for servicing, although less time is usually taken when 
more than one theater is in operation at a post. During each visit 
engineers are required first to satisfy reported irregularities in equip- 
ment operation since the last visit, then to inspect, test, and repair 
all sound, projection, and miscellaneous theater equipment, reporting 
unusual conditions encountered and the necessity and urgency for 
providing units, parts, or operating supplies; to instruct all pro- 
jectionists in the operation and maintenance of the equipment, han- 
dling of the film, and fire precautions. Such instructions must be in 



48 G. L. BUB [J. S. M. P. E. 

the form of demonstrations. Engineers, in addition to routine service 
work, also check ventilation, heating, and lighting equipment; re- 
surface screens; dismantle arc generator sets to have the armatures 
turned down locally; repair seats, vacuum cleaners, and ticket 
registers; in fact, advise and report on any and all factors in- con- 
nection with the theater, its equipment, or its technical operation. 
In spite of the fact that a complete set of replacement tubes, lamps, 
and fuses, take-up belts, and brushes are on hand in each projection 
room, and that each engineer's kit includes repair parts usually re- 
quired, it is on occasions necessary to wire the E. & M. Division for 




FIG. 7. Loud speaker terminal strips. 

replacement units or parts. These units and parts are installed 
either by the projectionists or the engineer, depending upon the 
nature of the replacement and experience of the projectionist. 

A necessary part of maintenance is the emergency call which, in 
some instances, is taken care of by a long-distance call made by the 
engineer nearest the theater. Projectionists following through on 
engineers' advice either solve the difficulty or assist in isolating 
the unit causing the trouble, in which case the engineer wires the 
K. & M. Division for the necessary part. However, all emergency 
calls can not be handled in this way; for example, a wire from a 



Jan., 1943] 



WAR DEPARTMENT THEATERS 



49 



theater officer advised that all projectionists but one had been trans- 
ferred and he had three theaters to operate that night. 

Other emergency calls have been equally unusual. In one case 
the difficulty was the result of crickets in a high-frequency baffle 
singing during the reproduction of a particular high frequency. 
Another resulted from mice gnawing away insulation, causing a short 
circuit. Repetition of a case of noisy reproduction was caused by 




FIG. 8. Engineer's kit of tools and instruments. 

vibrating tube elements when a nearby cannon was fired at retreat. 
The most serious emergency calls are those reporting either inter- 
mittent outages usually traced to a defective transformer, or binding 
shafts and stripped gears in projector mechanisms. 

Engineers of the Service are called upon to install or supervise the 
installation of all types of theater equipment under many and varied 
situations and are therefore given basic instructions in many fields. 
At the same time a certain leeway is allowed to encourage them to 
develop initiative, individuality, and resourcefulness. Engineers 



50 G. L. BUB [J. S. M. P. E. 

are required at times, for instance, to survey a post for a building 
most suitable for adaptation for use as a War Department theater. 
Such work requires general knowledge of all the factors entering 
similar work in civilian houses plus the special requirements of the 
Army. Whereas his main responsibility is that of a sound-projection 
engineer, he serves also in an advisory capacity for work in connection 
with building structure and building utilities. 

Providing replacement parts for regular and emergency servicing 
visits is but one of many responsibilities of the E. & M. Division, 
where provisions are established to meet promptly any request as 
regards sound and projection equipment. Instructing engineers is 
another. Representative equipment is set up at the E. & M. Divi- 
sion for operation in a test projection room equipped with regard to 
all fire precautions. 

In this projection room all types of amplifiers, supply units, warp- 
ing circuits, cross-over networks, auxiliary testing apparatus in- 
cluding oscillator, oscillograph, flutter meter, and a patch panel of 
plugs, receptacles, and switches arranged to operate any or all of this 
equipment, are mounted on a special rack (Fig. 4). All equipment 
reconditioned in the E. & M. Division is rolled into the projection 
room on dollies, plugged in to this rack and operated. All sound 
and projection equipment used in War Department theaters is re- 
conditioned, when required, at the E. & M. Division. All new types 
of sound and projection equipment are examined and tested here 
before purchase. Engineers' recommendations are considered and 
tested. Installation material and kits for all theaters are made up 
here. Projection room wiring plans originate here. The E. & M. 
Division machine shop fabricates not only replacement and modified 
units of equipment but items such as fire shutters (Fig. 5), portable 
switch panels, projector fuse blocks (Fig. 6), loud speaker terminal 
strips (Fig. 7), and many other items which assist in facilitating the 
installation and servicing work in the field. The engineer's kit of 
tools and instruments (Fig. 8) is organized here. It is here that the 
modifications cited previously were developed and tested. It is 
here that decisions are made as to the standards of sound and pro- 
jection equipments to be used, as to methods of installing, servicing, 
and maintaining sound and projection and miscellaneous equipments. 

The present emergency conservation of vital materials has brought 
about elimination of many refinements not only in equipment but 



Jan., 1943] WAR DEPARTMENT THEATERS 51 

in methods of installation and operation. For example, d-c arc 
switch panels and rubber cables have been eliminated. A "victory" 
projection-room wiring plan eliminates all conduit and junction 
boxes. Braid-x types of cables and loom have been substituted 
therefor. Carbons are burned at a minimum value of current. 
Copper drippings and copper coating from carbon stubs are being 
saved. With such conservation of materials, factors of safety and 
durability in installation and service work are also considered. 

In other words, the Engineering and Maintenance Division is dis- 
charging its responsibility of supplying the patrons of War Depart- 
ment theaters with the finest possible visual and sound reproduction. 



ADMINISTRATION OF U. S. ARMY MOTION PICTURE 

SERVICE 



R. B. MURRAY* 

In the presentation of a paper such as this, certain pertinent ques- 
tions form in the minds of listeners depending upon their particular 
interest; therefore, it seems appropriate that the administrative 
phases of the Service charged with the operation of the War De- 
partment theaters, the construction and the equipping of which have 
been described in the preceding papers, be presented on a question- 
and-answer plan. 

What Is the Purpose of Showing Motion Pictures on Army Posts? 
There are many ways in which this question may be answered, but 
the simplest one is that found in a remark by an enlisted man over- 
heard recently at Pine Camp, New York. Coming out of the War 
Department theater after the first performance, two soldiers paused 
to light their cigarettes, and one, looking out over the camp, said to 
the other, "Well, here we are again, back in the Army." 

The first task of the Army is to train men to fight. This involves 
not only skill in the handling of the implements of war, but the de- 
velopment and strengthening of the will to fight. Thus General 
Marshall, our Chief of Staff, recently said, "Napoleon evaluated 
morale over material as three to one. I believe that recent experiences 
indicate a reestimate of these values the odds being near five to one, 
or possibly even ten to one in some instances in favor of the psycho- 
logical factor." 

Recreation plays a very useful part in the maintenance of morale. 
It relieves taut nerves. For many who find the transition from 
civilian to military life most difficult, it provides the saving aspect 
of normality. Thus the Army has developed a broad program of 
service for the welfare, recreation, and education of its soldiers during 
their leisure- time periods. As a part of the effort made to direct the 
employment of their leisure hours in a manner beneficial to the morale 
and physical health of the men, attendance at motion picture shows 

* Director, U. S. Army Motion Picture Service. 
52 



U. S. ARMY MOTION PICTURES 53 

is encouraged. Coming in the evening when the men are restless, 
this type of entertainment is particularly valuable, as it affords a 
harmless emotional outlet otherwise difficult to find. 

Is the Service Fulfilling Its Mission? Following an inspection trip 
about a year ago, the Chief of Staff stated, "Everywhere I go, out 
with the troops, I find complimentary references to the operation 
of the War Department moving picture set-up." In a pamphlet 
entitled "Services for the American Soldier," published recently by 
the Joint Army and Navy Committee on Welfare and Recreation, 
appears the statement, "The backbone of soldiers' entertainment in 
posts and camps is provided by the Army Motion Picture Service 
which now operates the largest single theater chain in the United 
States." The files of the Service contain numerous letters of com- 
mendation for the Service and for individual employees, from post 
commanders. Typical comments are, "The Service has contributed 
immeasurably to the maintenance of the high morale of this com- 
mand," and, "The Service is having a great effect in keeping the 
young men away from undesirable resorts." An interesting and 
significant reaction was that explained recently by a post commander 
who stated he noted a tremendous improvement in the drill, dress, 
and bearing of recently arrived selectees immediately after the playing 
in the War Department theater of a film with a service background. 
The best measure of success is, of course, the attendance, which today 
is running at the rate of 118,000,000 a year. 

What Is the History of the U. S. Army Motion Picture Service? Dur- 
ing the last war, educational, recreational and welfare services were 
carried on largely through civilian agencies. Upon the recom- 
mendation of Dr. Raymond B. Fosdick, who headed the civilian 
agencies, and with the encouragement of Secretary of War, Newton 
D. Baker, an Army branch, concerned with all problems of morale, 
was formed. The motion picture phase was handled by entering 
into a contract with a commercial firm. This method proving to be 
most unsuccessful, the sole remaining step was for the War Depart- 
ment to form its own organization to carry on this work. Thus on 
January 1, 1921, the U. S. Army Motion Picture Service came into 
being. Those of us who were present at its birth will never forget 
how puny was the infant or how dismal was its outlook. Its foster- 
father was a well-wishing but skeptical War Department and its 
foster-mother an unsuccessful commercial concern. Its only assets 
were a woefully small sum of money with a discouraging official title 



54 R. B. MURRAY [J. S. M. P. E. 

of "Loss on Motion Picture Fund"; a few buildings which were 
theaters in name only; about enough World War I projectors to 
.permit one to a theater; and some devoted nurses who seemed to 
think the infant had latent possibilities. Though it suffered every 
known affliction and at times its very life was despaired of, its faithful 
nurses, sometimes blundering in their treatment but ever striving, 
grimly hung on, refusing to give up hope. One day the crisis was 
passed; the infant began to grow in strength and, once started, has 
ever thus continued. When it reached maturity on January 1, 1942, 
it rightfully felt that it occupied an indispensable niche in the Army 
establishment one that was carved out by its own endeavors. 

It is good, of course, that the Service grew up the hard way so that 
today, without being brash, it has the robustness, the experience, and 
the confidence engendered by the respect of an appreciative Army, 
which is so essential to the fulfillment of its mission for our vastly 
enlarged Army. 

Who Owns and Controls the U. S. Army Motion Picture Service? 
Literally and factually, the Service is owned by the military person- 
nel of the U. S. Army. It is operated by the Director of the Special 
Service Division of the Services of Supply, who is the trustee of the 
funds of the enterprise. Its policies and operating procedures are 
approved by the Secretary of War and published in Army Regu- 
lations. 

The Service was organized and continues to operate as a cooperative 
enterprise, in which all posts, camps, and stations were and are 
eligible for membership. The large posts, which are in the minority, 
provide by their membership the major portion of the total receipts. 
The small posts, which are in the majority, provide by their member- 
ship the large buying power which insures low-cost operation. Thus, 
all posts, both large and small, make a definite contribution to the 
enterprise. In return therefore the military personnel at all member 
posts receive a direct return in the form of the latest and best motion 
picture productions at a cost within their means. In addition thereto, 
the posts with populations sufficiently large to provide profitable 
operation are guaranteed a share in the profits, with the amount 
thereof approximating the total profit that these posts could expect 
to realize if they operated on an autonomous basis. With the ex- 
ception of minor changes effected from time to time, the present 
organization and its methods are practically identical with the 
original concept, and today, after many and varied difficulties, it 



Jan., 1943] U. S. ARMY MOTION PICTURES 55 

embraces even more completely the practical application of the 
"big brother" idea of profitable theaters at large posts rendering 
financial assistance for the maintenance of motion picture entertain- 
ment in non-profitable theaters at small isolated posts, where enter- 
tainment is considered most essential and where it could not otherwise 
be supplied. 

How Is It Financed? The Service operates, without benefit of 
Congressionally appropriated funds, on a self-sustaining basis through 
the receipts derived from the attendance of military personnel on a 
paid admission basis. It is true, of course, that the vast majority of 
its theaters today were constructed with public moneys and that the 
Service pays no rent for its use of the buildings. The Service pays 
the equivalent of rent, however, by reason of the fact that its equip- 
ment is used throughout duty hours for the projection of training 
films. 

What Is the Charge for Admission? Rates of admission are fifteen 
cents for single admissions and twelve cents when coupon books, 
containing coupons good for ten admissions, are purchased at a cost 
of $1.20. 

Why Is a Charge Made for Movies? The decision to operate on a 
self-sustaining basis was reached in the belief that more efficient 
service could thus be provided and a closer approach to a maximum 
response thereto secured than would be true in the case of a free 
service financed from appropriate funds. The necessity for the 
avoidance of an operational loss provides the incentive for efficiency 
in the management 6f the enterprise that insures the successful ac- 
complishment of its mission. 

What Becomes of the Profits? In the operation of the Service it is 
not the policy to accumulate funds in excess of those essential to the 
stability and continuity of the enterprise. Any profits realized are 
used to maintain the service at posts where losses are encountered; 
for distribution to posts with profitable theaters; for the purchase of 
new equipment; and for the general improvement of the Service. 
The profits distributed to posts with profitable theaters are made 
available to the post commanders for the general welfare of the 
garrison on projects or for purposes of a nature that, while considered 
either necessary or desirable, are generally of a character for which 
it is not considered proper to seek funds from the Congress. 

How Is the Service Administered? The Service is administered 
under generally accepted business principles. Its status as a business 



56 R. B. MURRAY [J. S. M. p. E. 

enterprise within a governmental framework naturally has increased 
the difficulties of operating what in itself is perhaps the most complex 
business in our economic structure. Fortunately, however, all the 
various Army officers who have controlled its destiny had the good 
sense to keep compliance with normal governmental procedure within 
reasonable limits. 

Operating under policies and procedures approved by the military, 
the Service is administered by civilian employees, all of whom are 
paid from its receipts. Its Executive Office, commonly termed the 
Home Office, is located in rented quarters in the city of Washington. 
In addition to performing the normal administrative duties of such 
an office, it advises in the construction of theaters, procures equip- 
ment and supplies, negotiates for film product, supervises the opera- 
tion of District and Branch Offices and the Engineering and Main- 
tenance Division, and manages the fiscal affairs. Accountability for 
its funds is lodged in a commissioned officer, known as the Fiscal 
Officer. Its accounts are audited semiannually by a firm of certified 
public accountants, and its overall operation is inspected yearly by 
the Inspector General of the Army. 

All negotiations and contacts with the home offices of the various 
film distributors are handled by a special representative permanently 
stationed in New York City. 

Six District Offices are located in New York, Washington, Atlanta, 
St. Louis, Dallas, and Seattle. Each District Office has a branch, the 
locations being Boston, Charlotte, New Orleans, Denver, San Fran- 
cisco, and Los Angeles. The principal duty of these field offices is 
the booking of films for the theaters located in their assigned territor- 
ies. The main duty of the district manager is the maintenance of a 
close personal contact with these theaters for the purposes of as- 
certaining the views of commanding officers on all matters pertaining 
to the Service and to advise with commanding officers and theater 
officers in all details relating to the administrative phases of the oper- 
ation of theaters. In short, the district manager bears the relation 
to the commanding officer of agent for the booking of film and of 
adviser in the administration of the theater. 

The Engineering and Maintenance Division is located in St. 
Louis. It is the duty of this division to install and maintain equip- 
ment in War Department theaters, which it is doing in the highly 
efficient manner indicated in the previous section of this paper. By 
a judicious use of engineers between the field work of installing and 



Jan., 1943] U. S. ARMY MOTION PICTURES 57 

servicing equipment and the shop work of repairing the various 
component parts thereof, maximum efficiency is achieved in the 
maintenance of equipment. Sacrifices in the appointments sur- 
rounding the audience have always been unhesitatingly made in 
favor of insuring perfection in what the patrons see on and hear from 
the screen. 

How Are Its Theaters Operated? Theaters are operated under the 
supervision of a commissioned officer selected and designated as 
theater officer by the post commander. The duties of this officer 
are the normal duties of a theater manager. He is accountable for 
all equipment, coupon books, admission tickets, and funds. He is 
responsible also for fixtures, the selection and supervision of person- 
nel, and the administrative operation of the theater in accordance 
with Army regulations. 

The various theater positions are filled by enlisted men who are 
appointed thereto by the theater officer. Since the performance of 
their duties is voluntary and on their free time, they are compensated 
therefor at rates ranging up to a maximum of $52 a month. At 
present approximately 5000 enlisted men are so employed at a total 
pay roll of over $1,600,000 a year. The positions consist of assistant 
theater manager, ticket cashier, ticket taker, chief projectionist, 
assistant projectionist, relief projectionist, and janitor. 

The starting times of performances are arrived at by the theater 
officer and are usually regulated to the supper hour of the men. 
Film programs are booked to arrive sufficiently in advance of showing 
to permit inspection, and repair if necessary, and transfer to house 
reels. The station notification form supplied by the district or 
branch office furnishes full information as to the titles of the subjects 
booked, the running time, and shipping instructions. The lower 
half of the form is utilized by the theater officer to report the ticket 
sales, the receipts, the condition of the film, and the audience re- 
action thereto. These daily reports are further utilized by the 
theater officer for the preparation of his weekly financial statement, 
which he forwards, along with all cash in excess of an authorized 
balance, to the fiscal officer of the Service. 

Within necessary limits, the theater personnel are trained to treat 
those admitted to the theater as patrons rather than members of the 
military. As in a civilian theater, order is maintained by the theater 
personnel by the exercise of tact and with resort to military police 
stationed outside the theater only when such means are ineffective. 



58 R. B. MURRAY [J. S. M. p. E. 

In line with accepted practice, fire regulations are posted and the 
theater employees are organized for proper action in case of fire. 
As to whether the safety of the patrons or of the building and its 
equipment is the greatest concern may possibly be deduced from the 
following typical incident. The World War Liberty Theater in use 
up until a few years ago at Fort Bragg, N. C., was heated by several 
hot-air furnaces installed under the auditorium floor. One night 
the floor over one of these furnaces began to smoulder. While the 
fire department was fighting the fire the audience continued to enjoy 
the picture until the smoke interfered with their vision of the screen, 
whereupon the audience moved over to assist in extinguishing the 
fire. They then returned to their seats to enjoy the rest of the 
picture. 

While exploitation stunts are not resorted to, an important duty 
of the theater officer is the advertising of programs. One-sheet 
boards are used, display frames are posted in the lobby, film trailers 
and heralds are judiciously utilized, and the programs are carried 
in the camp newspaper. The most effective advertising medium is 
a monthly calendar on which is shown the program for each day of 
the month. 

On What Basis Are Films Secured? The product of all film pro- 
ducers is available to and the best thereof is used by the Service. 
Price negotiations are conducted on the same basis followed by a 
commercial theater chain, special consideration, except as herein- 
after explained, being neither sought nor desired. Features are 
rented on a percentage basis, short reels on a flat rental basis, and 
newsreels on an age basis. The exception relates to the availability 
of product, pictures being made available on the basis of the number 
of prints required to enable all War Department theaters to play 
pictures within thirty days of their national release, without regard 
to the dates on which they may play neighboring civilian theaters. 
The necessity for this cooperation from the film industry is found in 
the many changes in station between home and battlefront made 
by a soldier from home to reception center, to replacement center, 
to the station of a tactical outfit, to staging area, to port of em- 
barkation, etc. 

Do Army Theaters Compete with Civilian Theaters? Throughout its 
existence, the Service has exerted every effort to insure its continuance 
in peace and war. It has at all times wisely recognized that unfavor- 
able action by film distributors on the basis of charges of unfair com- 



Jan., 1943] U. S. ARMY MOTION PICTURES 59 

petition from civilian exhibitors in communities adjacent to Army 
posts constitutes the greatest danger to its continuance as a Govern- 
ment instrumentality. Consequently, both from the viewpoint of 
self-preservation and the existence of a lively appreciation of the 
rights of civilian exhibitors whose investments may be at stake, 
every effort has been made to conduct the Service so that no legiti- 
mate grounds could exist for charges of unfair competition by the 
Army. All advertising issued is confined to the post; one-sheet 
boards may not be placed where they can be seen by the passing 
public, and attendance is restricted to military personnel, the mem- 
bers of their households, and civilians residing within the limits of 
the reservation. 

What Is the Booking Policy of the Service? The program schedule 
involves five changes a week. The two best pictures are shown for 
two days each and the next best three films are shown for one day 
each. On one of the single days a double-feature program is shown, 
consisting of two B pictures of the action type. The popularity of 
this latter program, started on a trial basis, has been such as to war- 
rant its continuance as long as this type of product is made. 

In the booking of film the Service functions as the agent of each 
post commander. Requests from his theater officer are honored 
when received, but in the absence thereof district and branch man- 
agers utilize their own judgment, under the supervision of the home 
office, based upon studies of attendance reports and the reactions 
of the audiences as reported by theater officers on the daily station 
notification reports. These reports are always valuable and some- 
times most interesting. Some of you may remember the Worcester, 
Mass., fire many years ago. Fox used red stock in filming the fire 
scenes, and, due to the magnitude of the fire, carried it in at least 
three issues of their newsreel. Following the showing of the third 
issue the report of one theater officer carried the comment, "Thank 
God Fox News didn't have a cameraman at the burning of Rome." 

What Kind of Features Do the Soldiers Likef The tastes of soldiers 
lean to music, comedy, and pictures with a Service background. It 
is immaterial whether the service background is the Army, the Navy, 
or the Marines. If one be asked to generalize, it could be said that 
the basic requirement is that the picture must "move" or our patrons 
will. 

Is There Any Censorship of Film Programs? No censorship is 
attempted other than over those pictures that portray U. S. Army 



60 R. B. MURRAY [J. S. M. P. E. 

life and activities. For the benefit of posts where the wives and 
children of Army personnel are stationed, the "mature" or "family 
audience" designation for each scheduled feature is supplied to 
theater officers so that they may inform all prospective patrons. 
These designations, which are based upon reviews by disinterested 
public agencies, are shown on theater calendars by the initials M and 
F. It was reported to us recently that a couple of young girls evi- 
dently had misinterpreted the initials M and F since, when leaving 
the theater, they were overheard to express a decided preference 
for the pictures marked for Male audience over those marked 
Female. 

What Is the Experience of the Service with Respect to Fires? 
Throughout its existence the Service has lost five buildings by 
fire, but not one of these losses was the result of a film fire. In one 
case, the projection room, with the equipment intact, standing 
precariously on four 6" X 6" columns, was all that remained of the 
building. Our projection rooms are fire-proofed to prevent fire 
originating therein from affecting the building, but in this case it 
worked in reverse. The fifth loss occurred about ten days ago, and 
it is believed the notice thereof that was received will be of interest. 
The wire read, "Theater building No, 8 this station practically 
destroyed by fire this morning. All equipment on stage and in au- 
ditorium totally destroyed. Projection and other equipment in pro- 
jection room slightly damaged by fire and smoke." The Service, of 
course, has had its share of film fires, but none of a serious character. 
Regulations emphasize that in case of a film catching fire in a pro- 
jection room no attempt is to be made by the projectionists to save 
the film or the machines, but rather one projectionist is to leave to 
report the fire and the other is to retire to a safe point of observation. 
Two violations of these instructions, amusing from this distance, 
come to mind. At Fort Snelling the original theater was a frame 
building in such condition as to necessitate having a fire-truck stand 
by whenever the theater was in operation. The firemen, who were 
watching the show, were suddenly called on to extinguish a fire on 
their truck, resulting from the action of the projectionist who had 
removed a burning reel from the projector and tossed it out the 
window into the fire-truck. We changed our standards for the di- 
mensions of observation ports following the action of a projectionist 
in our theater at Fort Myer many years ago, who hurled a burning 
reel through the porthole into the audience, at which point an obliging 



Jan., 1943] U. S. ARMY MOTION PICTURES 61 

patron picked up the burning reel and tossed it through an exit door 
into the street. 

What Is the Experience of the Service with Respect to Film Damage? 
Before the present emergency, damage to film was so negligible 
that often an entire year passed without a single claim of damage to 
film being presented by a film exchange. The operation of the 
Service at that time was stabilized from the standpoint of having 
experienced projectionists available. While some green film was 
used, the majority of the film had prior use and was therefore less 
easily damaged. However, with the tremendous expansion of this 
Service, it became necessary to train more projectionists quickly and 
schedule servicing visits with greater frequency. The change in 
film availability presented a steady diet of green film with its at- 
tendant problems. Then, too, the turnover in our volunteer force 
of projectionists was tremendous. Nevertheless, the amazing fact 
is that out of 1,695,620,000 feet of film projected in War Department 
theaters during the past twelve months, only 82,967 feet, or 0.0051 
per cent was damaged. This is a tribute not only to the equipment 
policies and the servicing personnel of the Service, but is also to the 
unusual interest in and aptitude for the exacting duty of projecting 
film displayed by our enlisted projectionists, the majority of whom 
never saw a projector before they entered the Armed Forces. 

What Is the Scope of Operation of the Service? The Army Motion 
Picture Service operates all War Department theaters in the forty- 
eight States, District of Columbia, Alaska, Newfoundland, Bermuda, 
and the Trinidad Sector of the Carribbean Defense Command. 
(Service for posts in the Hawaiian Department and the Puerto Rico 
and Panama Sectors is provided by similar organizations under the 
direction and control of the commanders thereof.) 

Are Motion Pictures Provided for Soldiers in Combat Areas? Sol- 
diers in theaters of operations throughout the world are supplied, 
without charge, with current releases in 16-mm form. The work is 
carried on by an agency of the Special Service Division known as the 
Overseas Motion Picture Service, U. S. Army, in the organization 
of which the U. S. Army Motion Picture Service assisted and 
to which it bears the relation of adviser. All expenses except film 
cost are paid from appropriated funds. The film, sufficient in quan- 
tity to insure at least three programs a week for all overseas forces, is 
donated to the armed forces by the American film industry, a mag- 
nificent gift of several million dollars. The film is made available 



62 R. B. MURRAY [j. s. M. p. E. 

without regard to release in this country, with the result that soldiers 
in far-flung parts of the world conceivably may see pictures before 
their home folks have the opportunity. As an example, a picture was 
shown on May 10, 1942, to soldiers in Iceland that was not shown 
anywhere in this country until July of that year. 

To What Extent Has the Service Expanded? This question can 
best be answered in statistical form as follows : 

No. of Theater Opening Date Elapsed Time 

One hundredth October 5, 1940 

Two hundredth April 5, 1941 182 days 

Three hundredth July 29, 1941 114 days 

Four hundredth January 29, 1942 184 days 

Five hundredth June 28, 1942 150 days 

Six hundredth September 20, 1942 -84 days 

Seventh hundredth November 18, 1942 59 days 

This work has been accomplished in the face of the difficulties, com- 
mon to all these days, incident to priorities, critical materials, loss 
of trained employees to the armed services, shortages of replacements, 
etc. By a combination of the imposition of a greater burden on will- 
ing backs and an all-out streamlining of administrative and opera- 
tional methods and procedures, the 600 per cent increase in theaters 
operated has been accomplished with an increase of but 275 per cent 
in civilian employees, the expansion here being from 81 to 304 em- 
ployees. The capacity of these 700 theaters is a little over a half 
million seats. Each week 4630 programs are exhibited. 

What Is the Outlook for the Service for the Duration? Present plans 
contemplate the establishing and operation of approximately 1000 
theaters, having a total capacity of 750,000 seats, in which 6750 
programs will be exhibited each week to an estimated yearly at- 
tendance of over 150,000,000. 

One of our veteran employees, when invited to assist in the prepa- 
ration of this paper, expressed regret over the fact that others in the 
film industry are denied the thrill that is one of the rewards received 
by employees of this service. What he had in mind was the op- 
portunity of seeing motion pictures in the actual process of sustaining 
morale. He was probably thinking generally of the thrill of watching 
hundreds of young soldiers streaming from all parts of their area, 
with the post theater their focal point. Undoubtedly he had in mind 



Jan., 1943] U. S. ARMY MOTION PICTURES 63 

the men in our far-flung defense outposts who are without even the 
probability of the action and the glory of battle to sustain their 
spirits. He referred specifically to his recent opening of a theater 
in a remote spot, outside this country, where howling blizzards, deep 
snow, cloudy skies, and sub-zero weather are a steady diet. The 
"auditorium" ceiling was but seven feet high, the screen a miniature 
on the order of 4 X 5, the viewing capacity about seventy not one 
of whom could stand while the others sat, else the picture would be 
on his back instead of on the screen. Architectural beauty was 
lacking; the surroundings could hardly be termed esthetic; the air 
was not conditioned in the accepted sense of the word; but on the 
screen was a perfectly projected image of the artistry of the world's 
finest film producers, and in the hearts of the men joy reigned. 
They were back on their own "Main Street," enjoying one of the 
finest of the all too readily accepted comforts of the American stand- 
ard of living. Forgotten were their surroundings, their loneliness, 
and the hardships of their daily lives. Forgotten for but a brief 
two hours, true, but who can doubt the therapeutic value of that 
period of escape from the insistent cares and realities of their situa- 
tions? Who would question that this magic screen, bringing news, 
comedy, romance, and glamor far removed from the rigors of their 
daily lives, could fail to refresh their mental and physical weariness 
against the resumption of tomorrow's burdens? Is there any cause 
for wonderment then as to why the Army accords motion picture 
entertainment such a leading role in the conditioning of its soldiers 
for the proper performance of their military duties? 

The Service feels that it has been signally honored in being per- 
mitted to tell something of its growth and expansion, and is delighted 
with this opportunity to express appreciation for the benefits it has 
derived in that connection from the accomplishments of the Society of 
Motion Picture Engineers. 



CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE 

ENGINEER 



The editors present for convenient reference a list of articles dealing with subjects 
cognate to motion picture engineering published in a number of selected journals. 
Photostatic copies may be obtained from the Library of Congress, Washington, D. C., 
or from the New York Public Library, New York, N. Y. Micro copies of articles 
in magazines that are available may be obtained from the Bibliofilm Service, Depart- 
ment of Agriculture, Washington, D. C., at prevailing rates. 



American Cinematographer 

23 (Dec., 1942), No. 12 

Explosions Made to Order (pp. 510-511, 528) 
How the Navy Makes Its Training Films (pp. 
513, 536-538) 

Republic Develops a New Custom-Built Camera 

Car (pp. 514, 528) 
Simplifying Script Breakdowns for Training 

Film Production (pp. 515, 534) 
Lighting Without Photofloods (pp. 520, 534) 

Applied Physics, Journal of 

13 (Nov., 1942), No. 11 
Color Television (pp. 666-677) 



Educational Screen 

21 (Nov., 1942), No. 9 

Motion Pictures Not for Theaters (pp. 348- 
350),Pt.41 

Electronics 

15 (Dec., 1942), No. 12 
Electron Tube Terminology (pp. 42-45, 154) 
Simple Harmonic Wave Analyzer (pp. 61-62, 

155) 

An Experimental Television System (pp. 68-71, 
170-178) 

Motion Picture Herald 

149 (Nov. 14, 1942), No. 7 
Sixteen Millimeter Operators Study Use of Field 

for Propaganda (p. 14) 
U. S. Plans Non-Theatrical Network for 16- 

Mm Films (p. 15) 
64 



B. WOLF 

A. W. ROHDE, JR., AND 

E. R. BUTTERLY 

W. SCOTT 

J. A. LARSEN, JR. 
W. STULL 



P. C. GOLDMARK, J. N. DYER, 

E. R. PlORE AND J. M. 

HOLLYWOOD 



A. E. KROWS 



W. C. WHITE 

R. F. THOMSON 

R. MAUTNER AND F. 

SOMERS 



SOCIETY ANNOUNCEMENTS 

ADMISSIONS COMMITTEE 

At a recent meeting of the Admissions Committee, the following applicants 
for membership were admitted into the Society in the Active grade : 

ARMSTRONG, V. D. CHANON, H. J. 

374 Selye Terrace, General Electric Co., 

Rochester, N. Y. 601 West 5th St., 

CALVIN, F. O. Los Angeles, Calif. 

The Calvin Co., HARGREAVE, ALFRED 

26th & Jefferson Sts., 141 Chestnut Hill Drive, 

Kansas City, Mo. Rochester, N. Y. 

HART, SIDNEY 

Downside Bannings Vale, 
Saltdean, Sussex, England 

In addition, the following applicants were admitted in the Associate grade : 
ALDEN, A. A. HARDING, J. A. 

460 West 54th St., P. O. Box 321, 

New York, N. Y. Hamilton, Bermuda 

ALNUTT, D. B. MCFARLANE, M. D. 

Mallinckrodt Chemical Works, Radiation Laboratory, 

3600 N. 2nd St., Mass. Inst. of Technology, 

St. Louis, Mo. Cambridge, Mass. 

BARNES, P. W. MERLE, J., JR. 

Det. 8th Signal Service Co., 2909 Meramec St., 

Fort Ord, Calif, St. Louis, Mo. 

DEFRENES, J. E. MILLER, EVERETT 

100 Broadview Rd. , 380 Bronxville Rd. 

Springfield, Dela. Cty., Pa. Bronxville, N. Y. 

GEORGE, P. J. POINDEXTER, JAY 

National Film Board, 365 W. Saxet Drive, 

Ottawa, Ontario, Canada Corpus Christie, Tex. 

STRALEY, WILKES 
607 West 38th St., 
Kansas City, Mo. 

The following members have been transferred from Associate to Active grade : 
GUNBY, O. B. Lo, T. Y. 

RCA Manufacturing Co. Inc., 1516 Spring Place, N. W., 

501 N. LaSalle St., Washington, D. C. 

Indianapolis, Ind. 

65 



MEMBERS OF THE SOCIETY 

LOST IN THE SERVICE OF 

THEIR COUNTRY 



FRANKLIN C. GILBERT 
ISRAEL H. TILLES 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

VOLUME XL FEBRUARY, 1943 



CONTENTS 

PAGE 
Report of the Theater Engineering Committee 71 

Copper and Sulfide in Developers 

R. M. EVANS, W. T. HANSON, AND P. K. GLASOE .88 

Factors Affecting the Accumulation of Iodide in Used 
Photographic Developers 

R. M. EVANS, W. T. HANSON, AND P. K. GLASOE 97 

The Effect of Developer Agitation on Density Uni- 
formity and Rate of Development 

C. E. IVES AND E. W. JENSEN 107 

Society Announcements 137 



{The Society is not responsible for statements of authors.) 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

SYLVAN HARRIS, EDITOR 

ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 

** President: HERBERT GRIFFIN, 

90 Gold Street, New York, N. Y. 
** Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
** Executive Vice-President: LOREN L. RYDER, 
5451 Marathon Street, Hollywood, Calif. 
^Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Avenue, New York, N. Y. 
** Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 

* Financial Vice-President: ARTHUR S. DICKINSON, 

28 W. 44th Street, New York, N. Y. 
**Convention Vice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
^Secretary: E. ALLAN WILLIFORD, 

30 E. 42nd Street, New York, N. Y. 

* Treasurer: M. R. BOYER, 

350 Fifth Ave., New York, N. Y. 
Governors 

*H. D. BRADBURY, 411 Fifth Avenue, New York, N. Y. 

*FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 

*ALFRED N. GOLDSMITH, 580 Fifth Avenue, New York, N. Y. 

*A. M. GUNDELFINGER, 2800 S. Olive St., Burbank, Calif. 

*CHARLES W. HANDLEY, 1960 W. 84th Street, Los Angeles, Calif. 

*EDWARD M. HONAN, 6601 Romaine Street, Hollywood, Calif. 

*JOHN A. MAURER, 117 E. 24th Street, New York, N. Y. 
**WILLIAM A. MUELLER, Burbank, Calif. 

*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
**H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**JOSEPH H. SPRAY, 1277 E. 14th Street, Brooklyn, N. Y. 
**REEVE O. STROCK, 195 Broadway, New York, N. Y. 

*Term expires December 31, 1943. 
**Term expires December 31, 1944. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, include! 
in their annual membership dues; single copies, $1.00. A discount on subscription or singl 
copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motioi 
Picture Engineers, Inc., 20th and Northampton Sts., Easton, Pa., or Hotel Pennsylvania, 
York, N. Y. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1943, by the Society of Motion 

Picture Engineers, Inc. 



REPORT OF THE THEATER ENGINEERING COMMITTEE* 



Summary. A combined report of the Sub-Committees on Projection Practice, on 
Civilian Defense in Theaters, and on Screen Brightness. Of especial importance is 
the "Report and Recommendations on Proposed Mechanical Methods for Film 
Conservation," of the Projection Practice Sub-Committee, and which has already had 
wide distribution throughout the motion picture industry. 

The Sub-Committee on Civilian Defense presents a program of defense mesaures to 
be studied with a view of making suitable recommendations for defense to the in- 
dustry. 



At the outset of this report, it may be stated that the Chairman and 
the personnel of the Theater Engineering Committee, including the 
members of the Sub-Committees, realize that the demands made 
upon the various members in cooperating with the war effort, or as a 
result of being actually engaged in technical work for the armed 
forces, make it difficult to pursue the usual committee activities in 
peacetime fashion. Nevertheless, it is gratifying to report that much 
work of a constructive and important nature has been accomplished 
by the Theater Engineering Committee, some of which, as will be 
noted below, is directly related to the war effort. Many new things 
are coming out of the war, and it may prove that the technical ex- 
perience and knowledge of SMPE committees, such as the Theater 
Engineering Committee, will be found to be of major importance, not 
only to the civilian motion picture industry, but as well to the mo- 
tion picture activities of the Government. 

The Theater Engineering Committee, therefore, has endeavored to 
maintain its scope of activities on as broad a plane as possible under 
the present trying circumstances; and accordingly it is with gratifi- 
cation that the Chairman is able to present in this report an account 
of work done during the past six months that should be regarded as 
important as any the Committee has done in the past. 



* Presented at the 1942 Fall Meeting at New York, N. Y.; received October 25, 
1942 

71 



72 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E. 

There are four Sub-Committees of the Theater Engineering Com- 
mittee, namely, (1) Projection Practice, (2) Motion Picture Screen 
Brightness, (3) Motion Picture Theater Design, and (4) Civilian 
Defense in Theaters. The last named sub-committee was established 
by the Board of Governors several months ago, and has been holding 
meetings at frequent intervals. Its first report is included herewith. 

SUB-COMMITTEE ON PROJECTION PRACTICE 

During the past six months the Sub-Committee on Projection 
Practice has been actively engaged in problems directly related to the 
war effort. The first of these was the question of "Wartime Conser- 
vation in Theater Projection," and in the June, 1942, issue of the 
JOURNAL there was published a very complete discussion of methods 
of conserving both film and motion picture equipment in the theaters. 
This report was an elaboration of a ten-point program of conserva- 
tion originally proposed by Mr. Richard Walsh, president of the 
International Alliance of Theatrical and Stage Employees, and the 
War Activities Committee of the Motion Picture Industry, and was 
presented at a meeting of the Atlantic Coast Section of the Society at 
New York on May 21st. The meeting was attended by several 
hundred projectionists of the New York Metropolitan area, and the 
report received wide attention in the motion picture trade press. 

Following this report, the third revision of the Projection Room 
Plans was published in the September, 1942, issue of the JOURNAL. 
The original plans were published in August, 1932, with revisions in 
October, 1935, and November, 1938. Such revisions are necessary 
from time to time in order to keep pace with the changes and develop- 
ments in the art and practice of projecting sound motion pictures and 
to make sure that projection rooms are so planned as to permit maxi- 
mum efficiency of operation of the equipment installed within them. 
These recommendations have received wide acceptance throughout 
the entire industry, and have also been reprinted in all the major 
trade publications. 

During the month of August, it became known to the industry that 
the Military and Civil Departments of the Government were using 
motion picture film in very large quantities in fact, it subsequently 
developed that the quantities of film involved were so great that the 
Motion Picture Film Manufacturers would have difficulty in supply- 
ing enough film for both civilian and government use. Accordingly, 
much attention was given to possible ways and means of conserving 



Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 73 

film, or of reducing the quantity of film used by the civilian Motion 
Picture Industry. The situation was accentuated by the fact that 
early in September stocks of motion picture film were "frozen" by 
the War Production Board. 

Several meetings of the Projection Practice Sub-Committee were 
called for the purpose of studying a number of proposals that were 
made for reducing, by mechanical means or changes in equipment, 
the quantity of film used by the Motion Picture Industry. It was the 
unanimous opinion of the Sub-Committee that the question of 
film conservation should be given very serious attention, and that 
everything possible should be done to accomplish the desired results. 
Although several such specific mechanical means had been proposed, 
it was the opinion of the Sub-Committee that the entire question 
should be considered in a broad and technically sound way that is, 
to determine what would be the consequences of adoption by the 
industry of any system whatsoever of conserving film by mechanical 
changes in equipment. Regardless of the nature of the system, 
questions would arise in connection with materials available for mak- 
ing the change from the present to the proposed system, labor neces- 
sary for making the parts, the availability of expert mechanics and 
machinists, the possibility of the diversion of such material and labor 
to this work from important war industries; and accurate estimate of 
how many changes would be required to install a new system; the 
performance levels resulting from the change; and many other simi- 
lar and relevant questions. 

As a result of several meetings by the Projection Practice Sub- 
Committee, the following "Report and Recommendations on Pro- 
posed Mechanical Methods for Film Conservation" evolved. This 
report was begun, as mentioned above, as a project of the Projection 
Practice Sub-Committee of the Theater Engineering Committee. It 
developed, however, that the question of conserving film by mechani- 
cal means involved not only questions of projection, but embraced 
as well, th production and distribution branches of the industry. 
Accordingly, through the efforts of the Chairman of the Theater 
Engineering Committee and the Engineering Vice-President of the 
Society, other technical committees of the Society were brought into 
the work of preparing this report. It should be emphasized that the 
following report represents a valuable piece of work brought about by 
collaboration of a number of SMPE technical committees. In view 
of the great urgency of the question, the report was made available to 



74 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E. 

the trade press prior to publication in the JOURNAL, and has been 
called to the attention of the Military and Civil Departments of the 
Government and the Motion Picture Industry. The report follows : 



REPORT AND RECOMMENDATIONS OF THE SOCIETY OF MOTION 

PICTURE ENGINEERS ON PROPOSED MECHANICAL METHODS FOR 

FILM CONSERVATION 

PREAMBLE 

In presenting to the Civil and Military Departments of the Govern- 
ment and the motion picture industry its detailed recommendations 
relative to recently proposed methods for conserving film by physical 
changes in the picture and sound processes and equipment, the So- 
ciety of Motion Picture Engineers desires to state its reasons for such 
action and to define its general attitude. 

The motion picture industry of today represents an outstanding 
triumph of technology. It is based on the work of engineers, manu- 
facturers, writers, directors, actors, producers, laboratories, ex- 
changes, theater exhibitors, and theater-operating personnel. It has 
been built up to its present high standards through the last forty 
years of painstaking and intelligent effort, trial and error, scientific 
and engineering development, and artistic evolution. It has won 
public acceptance on an amazing and gratifying scale. The good will 
of the public toward the motion picture and the place which the cine- 
matic art fills in the lives of our citizens must never be lightly jeopard- 
ized. Doubly is this the case in times of war, for now the motion 
picture is not only a means of entertainment and education but also 
a great builder of morale, a relaxation for tired nerves, a rejuvenator, 
and a spur to greater national effort toward our ultimate victory. 

The Society of Motion Picture Engineers is accordingly deeply 
interested in the preservation of the hard-won standing and achieve- 
ments of the motion picture industry. It is opposed to any unwar- 
ranted change, to any step of which the consequences have been in- 
sufficiently analyzed, or any precipitate and insufficiently considered 
basic change in technological methods. It must be vigorously stressed, 
however, that the Society does not oppose change as such, but is 
strongly in favor of the prompt adoption of demonstrable improve- 
ments. The Society is thoroughly open-minded and judicial in these 
matters. It has no preference for any organization or method as 
such, nor yet any prejudice or opposition toward suggested forward 



Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 75 

9\ ' 



steps in the art. It does believe, however, that thorough analysis of 
any proposed technological change must be carried out with experi- 
mental verification by means of neutral engineers prior to its wide- 
spread adoption. It believes further that any claimed economies or 
simplification should be subject to experimental verification on a 
small scale in the hands of competent technical observers prior to 
their adoption. 

Otherwise stated, the Society of Motion Picture Engineers regards 
with the utmost seriousness any radical change in industry methods. 
It is heartily in favor of the adoption of any such methods as, after 
careful analysis and experimental verification on a minor scale, are 
proved practicable. It is opposed to hasty and experimentally un- 
supported action on a large scale. It urges the industry and the gov- 
ernment to consider the insurance value of determining basic facts 
before making fundamental modifications. It stands for completely 
fair and open-minded investigation of facts and prompt action based 
on such investigation. 

The Society of Motion Picture Engineers offers to the government 
and the motion picture industry the following definite recommenda- 
tions and plan for carrying them into effect, including a detailed 
questionnaire embodying those points which must with propriety and 
for the sake of safety be considered by those neutral engineering in- 
vestigators who may study experimentally any proposed physical 
methods of reducing film consumption. In doing this, the Society 
believes it is freely rendering a valuable and constructive service to 
the motion picture industry and the Government and is fulfilling one 
of its major purposes. So far as the Society can appropriately and 
effectively be of further service, it will endeavor to assist the Govern- 
ment on our road to victory, and to help the industry to maintain its 
high standing and its efficiency of operation. 

SECTION I 

Resolution 

That a carefully selected group of neutral, competent motion pic- 
ture engineers should be retained by the motion picture industry, 
the Government, or both ; that they should be provided with means 
for the construction, reconstruction, and comprehensive operating 
tests of relevant equipment; and that they should report with all 
reasonable promptness, consistent with the collection of adequate 
data and the analytical formulation of valid conclusions, to the mo- 



76 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E. 

tion picture industry, the Society of Motion Picture Engineers, and the 
Academy of Motion Picture Arts & Sciences, on all relevant operat- 
ing data, cost data, material requirements, material savings, indus- 
try procedure, and recommendations relevant to all promising sub- 
mitted methods for conserving motion picture film in the theater 
field. 

The work of these engineers will presumably include, if neces- 
sary, the modification of cameras, sound recorders, composite-shot 
equipment, studio projectors, moviolas, laboratory processing equip- 
ment, exchange equipment, theater projectors and sound equipment, 
and special equipment (e. g., color motion picture equipment). 

Among the questions to be answered by the neutral engineering 
group mentioned above, the following are basic and should receive 
especially precise and detailed treatment : 

SECTION n 
Production 

I. Slulio Practice 

(A) Cinematography. (1) Will the proposed system require 
changes in camera equipment? 

(a) Will alteration of sprockets, pull-down mechanisms, cams, 
etc., be necessary in all cameras, and if so, will the changes be readily 
adaptable to all makes and types of presently available cameras? 

(b) Will the camera drive motors and interlock mechanisms now 
in use require alteration ? 

(c) Will presently used lens equipment be adaptable, or will new 
lenses of different focal lengths be required? 

(d) If the camera aperture is changed, what will the dimensions 
and aspect ratio be? 

(2) Will the proposed system be similarly adaptable to the vari- 
ous color cinematography equipments? 

(3) How will present background projection processes be af- 
fected? 

(4) Would it be practicable to operate with present standard 
cameras and equipment, making the necessary changes in the print- 
ing process? 

(B) Sound. (1) What changes in sound recorder and re-recorder 
mechanisms are essential for operation of the proposed system (e. g., 
sprockets, scanning system, etc.) ? 



Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 77 

(2) What changes in sound recorder and re-recorder mechanisms 
are desirable for satisfactory operation of the proposed system (e. g., 
mechanical filtering, scanning-slit dimensions, etc.) ? 

(3) What other changes must be made in sound equipment or 
technique (e. g., equalization recording level, pick-up technique, 
mixing noise reduction, etc.) ? 

(4) Would it be practicable to operate with present standard 
sound -recording equipment, making the necessary changes in re- 
recording or printing processes? 

(5) Will any changes be necessary in other sound equipment 
(e. g., reproducers, moviolas, effect equipment, etc.)? 

(C) Physical Properties (Sets). (1) Will the proppsed system 
necessitate any changes in the regular routine of picture production? 

(a ) Will changes be required in set lighting techniques ? 

(b) Will studio sets be changed in size and proportions ? 

(c) What other changes are required in the general physical set-up 
of studio operation? 

(D) Cutting and Editing. (1) Will different techniques be re- 
quired in the normal practice of cutting and editing picture and 
sound-track negatives? 

(a) What changes in equipment will be necessary (e. g., rewinds, 
moviolas, splicers, etc.)? 

(E) General. (1) Will the proposed system readily adapt itself 
to present 16-mm production technique, considering that it is often 
essential that 16-mm and 35-mm subject material be inter-cut? 

(2) Will studio review rooms require alteration (similar to theater 
alteration) ? 

//. Laboratory Practice 

(A) Printers. (1) Will mechanical alterations be required in 
printer equipment? 

(a) How will continuous picture printers be changed? 

(b) Will intermittent picture printers be altered? 

(c) Will alterations be required in sound printers? 

(d) Will changes be required in light change equipment and 
interrupter mechanisms? 

(2) What changes will be required in optical and trick effect 
machinery? 

(B) Developing Machines. (1) Will changes be indicated in de- 
veloping machines? 



78 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E. 

(C) Negative Handling. (1) Will negative handling methods be 
changed (e. g., splicing, roll lengths, cue marks, notches, etc.] ? 

(D) Print Inspection. (1) Will changes have to be made in 
print inspection techniques, i. e., alteration of special type high-speed 
inspection projectors, etc.? 

(2) Will changes be required in print-splicing techniques ? 

(E) Raw Stock.- (1) Will different standards of raw stock supply 
be required, i. e., width perforation standards, unit reel length, etc? 

(F) General. (1) Will the unit length of print shipments from 
the laboratory to the exchange depots be altered ? 

(2) Will the production capacity of the laboratory be affected, 
either in footage capacity or "entertainment minutes" production 
ability? 

(3) What changes will be required in laboratory equipment to 
produce 16-mm prints from negatives made according to the pro- 
posed standard? 

(a) Will mechanical changes be required in continuous and inter- 
mittent projection printers and in 16-mm contact printers? 

(4) What changes will be required in color laboratories (e. g., 
registering printers and special processing equipment, special registry 
films, etc.) ? 

Distribution 

(I) Exchange 

(A) Transportation. (1) Will changes be required in shipping 
containers? 

(B) Exchange Office Operation. (1) Can prints be mounted on 
standard present size reels? 

(2) Will different size reel bands be required ? 

(3) Will alterations of the different types and kinds of splicers be 
required? 

(4) Will changes be necessary in vault and storage facilities? 

(5) Will changes be required in exchange review rooms (similar to 
theater operation) ? 

Exhibition 

I. Theater Operation 

(A) Projection Equipment. (1) Projector Picture Heads: 

(a) What changes will be required in each type of projector s mech- 



; 

Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 79 

anism to accept film of the new proposed standards (e. g., sprockets, 
idlers, aperture, etc.) ? 

(b) What change may be desirable in each type of projector mecha- 
nism to accept film of the new proposed standard (e. g., shutters, 
lenses, etc.)? 

(c) Is it planned to retain the present picture proportions? If 
not, what will be the new proposed dimensions and the new proposed 
picture aspect ratio? 

(d) Will it be practicable for the projectionist to make the pro- 
posed modifications in the theater and without the assistance of out- 
side experts? 

(e) If not, will it be practicable for the projectionist to make the 
proposed modifications in the theater and with the aid of outside ex- 
perts ? If so, what organizations are, or will be, available to make these 
modifications? 

(/) If neither (d) nor (e) are practicable, what special facilities 
and personnel will be necessary to make the proposed modifications? 

(g) What is the space between consecutive frames on the film in 
the proposed system ? If it is different from the present standard, how 
does it affect projection? 

(h) Will the angular velocities of the projector parts differ from 
the present standards? If so, what will they be and what will the 
effect be upon the life of the projector? 

(2) Projector Lamp-Houses : 

(a) What changes, if any, will be necessary in each type of lamp- 
house to accommodate it to the proposed system (e. g., carbons, op- 
tical systems, etc.) ? 

(3) Projector Sound-Head and Associated Equipment: 

(a) What changes will be required in each type of sound-head to 
accept film of the new proposed standards (e.g., sprockets, idlers, etc.) ? 

(b) What change may be desirable in each type of sound-head to 
accept film of the new proposed standards (e. g., scanning system, 
etc.)? 

(c) Will the width and position of the sound-track differ from the 
present standards? If so, what will the proposed new standards be? 

(d) Will it be practicable for the projectionist to make the pro- 
posed modifications in the theater and without the assistance of out- 
side experts? 

(e) If not, will it be practicable for the projectionist to make the 
proposed modifications in the theater and with the aid of outside ex- 



80 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E 

perts? If so, what organizations are, or will be, available to make 
these modifications? 

(/) If neither (d) nor (e) are practicable, what special facilities and 
personnel will be necessary to make the proposed modifications ? 

(g) Will the angular velocities of the sound-head parts differ from 
the present standards? If so, what will they be and what will be the 
effect upon the life of the sound-head? 

(h) If the film speed is changed, what changes in quality of sound 
reproduction will result? By what means can objectionable effects 
be reduced, to what extent, and with what additional resulting effects 
(e. g., changes in frequency characteristics of theater reproducing 
systems, changes in scanning systems, studio preequalization, ampli- 
fier gain, mechanical filtering in the sound-head, etc.) ? 

(1) Will the new systems change mediocre or just average sound 
reproduction to inaccep table reproduction? 

(B) Film. (1) What effect do the following factors have, both 
individually and collectively, upon the life of the film and safety of 
operation? 

(a) Change of linear speed. 

(b) Change of sprocket diameters (number of teeth engaging) . 

(c) Change of film tension. 

(d) Change of film temperature at the aperture. 

(e) Other relevant factors. 

(C) Screen. (1) What changes, if any, will occur in the dimen- 
sions and aspect ratio of the screen image, and will re-masking or 
screen replacement be necessary? 

(2) What change, if any, will there be in screen brightness? 

(3) What change, if any, will there be in picture quality (e. g., 
definition, flicker, steadiness, etc.) ? 

(4) Will the new systems change mediocre or just average pic- 
tures to inacceptably soft pictures? 

(D) General. (1) From an engineering standpoint, will the pro- 
posed system represent an advance in the art of projecting motion 
pictures? 

(2) What effect will the proposed modification have upon the 
theater audience? 

(3) What effect, if any, will the proposed modification have upon 
the fire hazards and safety in theater operation? 

(4) Will the proposed change be temporary or permanent? 

(5) Will the proposed system be readily interchanged with the 



Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 81 

existing system in order that present standard prints may be pro- 
jected when desired? 

(6) How much film will the proposed system conserve annually? 



General 

(1) What will be the total cost to the motion picture industry, 
the military forces, and the U. S. Government agencies to make the 
adaptation to the proposed system in terms of materials, man-power, 
manufacturing facilities, and time? 

(a) What will be the total cost in these specified terms to put the 
system into practice in the studios of the motion picture industry? 

(b) What will be the total cost in these specified terms to put the 
system into practice in the laboratories of the motion picture in- 
dustry? 

(c) What will be the total cost in these specified terms to put the 
system into practice in the exchanges of the motion picture industry? 

(d) What will be the total cost in these specified terms to put the 
system into practice in the theaters of the motion picture industry? 

(e) What would be the individualized costs to the military forces 
and the various agencies of the U. S. Government to make each of the 
specific changes as mentioned in (a), (b), (c), and (d)? 

(2) What is the availability of all the various types of needed 
materials, manufacturing facilities, and man-power required, con- 
sidering the present emergency conditions? 

(3) Can or will military forces and government agencies readily 
adapt their present production, distribution, and exhibition program 
to the proposed standards? 

(4) Will the adoption of the proposed system make the supply 
and inventory of standard parts for various types of motion picture 
equipment obsolete? 

(5) What total length of time would be required to completely 
adapt the equipment used for the present standard production, dis- 
tribution, and exhibition, to the proposed system? 

(6) Can an adequate supply and inventory of new parts be made 
readily available as the adaptation of the new system progresses? 

(7) Would it be practicable to issue prints of both the present 
standard type and also the new proposed system, simultaneously? 

(8) What effect will the proposed standard have upon the reissue 
of pictures, produced under the present standard, which are now 



82 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E. 

stored in libraries of the motion picture industry, the military forces, 
and agencies of the U. S. Government? 

(9) During any conversion period, at what rate would the pro- 
posed film savings approach the expected maximum? 

SECTION in 
Further Procedure 

The Society of Motion Picture Engineers is prepared to assist the 
Government, upon request, in any feasible way, in directions in which 
it is qualified in order to contribute toward the war efforts of the 
United States. It will continue to endeavor to cooperate further with 
the motion picture industry to protect and raise the high repute and 
favor in which the motion picture is held by the public. 

Any call for its future collaboration with the Government or the 
industry will, as in the past, be promptly and effectively heeded. 

SUB-COMMITTEE ON CIVILIAN DEFENSE IN THEATERS 

The Sub-Committee on Civilian Defense in Theaters was formed 
for the purpose of assisting theater operators in technical questions 
relating to civilian defense. There is an unmistakable indication that 
theater management needs and wants technical advice on certain of 
its civilian defense problems. 

Representatives of theater management find themselves confronted 
by an extremely large number of special devices advocated for various 
purposes. In most instances the management lacks the technical 
facilities or training for correctly evaluating these devices. 

The Office of Civilian Defense has issued general regulations re- 
lating to theaters but these regulations permit great latitude and dis- 
cretion to management and leave to managment the solution of many 
technical problems. It is the intent of the Sub-Committee to cooper- 
ate with the Civilian Defense Authorities. As new regulations are 
issued, the Committee will study the problems arising therefrom. 
It is its hope that out of the activities of the Committee will arise a 
manual or series of bulletins which can be placed in the hands of the 
industry for guidance in technical matters relating to civilian defense. 

A theater presents one of the most acute civilian defense problems 
because of the large number of persons involved. Theaters are to 
continue to operate under air-raid conditions so that the problems 
must be faced and solved. The war may be of long duration, and 



Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 83 

therefore many measures are of a semi-permanent nature. The Com- 
mittee will not, for the present at least, cover the routine of air-raid 
drills, the organization of theater staffs, the actual handling of pa- 
trons, and the like. It is believed that its most valuable service will 
be in the solution of purely technical problems relating to physical 
equipment. 

The Sub-Committee membership has been so selected that the 
technical field is broadly covered. It is its intention, however, to 
bring into consultation with it important representatives of manu- 
facturers, technical bureaus, civilian defense authorities, and many 
others, as required by the variety of technical problems involved. 
The Sub-Committee plans to be a clearing house for information re- 
ceived from the general membership and from outside sources. 

Some problems have been solved since the formation of the Sub- 
Committee. At the time of its creation, bomb extinguisher powders, 
snuffers, tongs, and other devices for handling and extinguishing in- 
cendiary bombs were being sold to theater operators. Recently, the 
National Board of Fire Underwriters, with the approval of the Office 
of Civilian Defense, has declared that such powders are not materi- 
ally better than sand, dry dirt, or ashes, and are therefore not recom- 
mended. The spray method of extinguishing incendiary bombs, 
which was considered questionable by certain members of the Com- 
mittee, has been largely superseded by the solid jet or stream method. 
While many of the improper devices may not be harmful in them- 
selves, nevertheless, their adoption by uninformed management may 
lead a false sense of security and prevent the adoption of the best and 
most effective equipment. 

One of the purposes of this report is to request the membership to 
submit to the Sub-Committee its technical problems relating to 
civilian defense, and what is more important, to ask the membership 
to contribute to the Committee, for the benefit of the industry and 
consequently of the nation and its war effort, all its knowledge which 
may be of assistance in connection with theater civilian defense. 

The Sub-Committee is fully appreciative of the limitations arising 
out of shortages of material, equipment, and skilled labor, and re- 
alizes that it will be necessary in many instances to compromise, 
and depart from ideal conditions and from established codes and 
regulations, and make the best of conditions as they are. 

It is conscious of further limitations, for any committee of an en- 
gineering society must avoid even an appearance of commercialism 



84 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E. 

or, as a general rule, of advocating or favoring any one of a limited 
number of patented devices. The Committee does not know as yet 
to what degree this may hinder its efforts, but it realizes this may con- 
stitute a stumbling block to giving the best service. It has already 
collected a great amount of data, but at the present time it would 
like to have further information upon, and the benefit of your ex- 
perience, with the following : 

Emergency Lighting Systems. The Sub-Committee would like to 
provide theater management with definite data upon, and sug- 
gested layouts for, simple emergency lighting systems. It would 
like to advise on the types and capacity of batteries and other current 
supplies; permissible lengths of wiring; voltage drop with different 
lengths and diameters of wire; suitable lenses to obtain proper dif- 
fusion for general or specific illumination; relays for automatically 
operating lighting systems, and related topics. 

It is its intent to call in representatives of manufacturers of these 
devices and have them explain to the members the merits and prop- 
erties of the devices, and it will attempt to determine their limitations 
and then to suggest to the membership or to theater management the 
best types of device for their use. 

Shatter Resistant Glass. A theater has of necessity a certain amount 
of glass included in its construction. The stage skylight is necessarily 
of glass and as a rule there are glass mirrors. There is plate-glas c i n 
the box-office, the theater doors, and in certain windows. Re^ ,. 
on this subject has been carried on by the Bureau of Standards and 
other organizations. The reports are, however, generally too cumber- 
some or technical for theater management to absorb. The Sub-Com- 
mittee will analyze the results of this research and present them in 
reasonably non-technical form for the benefit of the theater managers. 

Blackout Materials. Here again theater management is confused 
when confronted by an endless variety of liquids, plastics, and tex- 
tiles for application to glass to render it non-transparent. The in- 
surance companies have already sustained substantial plate-glass 
losses because of the application of black paints to glass with conse- 
quent rise in temperature and cracking of the glass. The Sub-Com- 
mittee will call into consultation engineers from the plate-glass in- 
surance companies and consult with them upon this subject and 
relevant subjects. It will also confer with the manufacturers of glass 
and of coating materials. Meanwhile, it would value the contribu 
tions of members of the Society on this subject. 



Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 85 

Luminous Paints. Too little is known about this subject by 
theater management. Use of phosphorescent or other luminous 
paints, unless under predetermined conditions, may be worse than 
useless. In this instance, as in others, a false sense of security may be 
engendered and the use of phosphorescent materials may prevent the 
use of some more effective method. The Sub-Committee will examine 
particularly their suitability for outdoor purposes. It will explore 
the whole subject with the thought of developing the advantages but 
pointing out the limitations of luminous materials. 

Structural Protection. While as yet there has been little tendency 
toward protecting buildings in this country by sandbags, barricades, 
and the like, or by making structural changes to increase bomb re- 
sistance, nevertheless questions may arise, and the Sub-Committee 
will keep itself informed on this subject. It hopes to determine the 
best method of protecting a stage skylight against falling missiles. 
It may recommend the examination and possible strengthening of 
long span theater roofs, the improvement of exit facilities, and selec- 
tion and improvement of certain parts of the theater, such as lobbies 
and large rest-rooms as air-raid shelters. Removal of chandeliers may 
be recommended. 

Fire-Fighting Equipment. The Sub-Committee will study the 
recommendation of the National Board of Fire Underwriters and the 
^iV ; Han % Defense Authorities as to the equipment desirable or neces- 

j *<^f handling and extinguishing incendiary bomb and other fires, 
it will endeavor to keep itself informed on the latest development and 
in turn so inform the industry. 

First- Aid Equipment. As far as it is within its province to do so, 
the Sub-Committee will study first-aid equipment and first-aid room 
requirements. 

Miscellaneous Equipment. From time to time, miscellaneous de- 
vices will be developed. New needs will arise. The Sub-Committee 
will be prepared to assist where needed. 

Inter- Communication Systems. In the larger theaters particularly, 
there is need for system of inter-communication between the various 
parts of a theater during the occurrence of an emergency. The Sub- 
Committee will endeavor to keep its recommendations along these 
lines to a minimum. 

Notification Systems. Various arrangements have been made for 
notifying the audience of the occurrence of an air-raid emergency. 
Some theaters depend upon verbal notification from the manager 



86 THEATER ENGINEERING COMMITTEE REPORT [J. S. M. P. E . 

from the stage. Others have provided slides. There has been some 
discussion of using trailers, illuminated signs, or other means. The 
Sub-Committee will attempt to present to the industry as much in- 
formation as is available on this subject, and here particularly it 
would appreciate having the advice and experience of the member- 
ship and the industry. 

Sabotage. The Sub-Committee will determine the extent to which 
it may be proper for the Committee to explore methods of prevention 
of sabotage in theaters. 

These are only a few of what appear at this time to be the more im- 
portant questions confronting the Sub -Committee. Conditions are, 
however, so changeable that it may be confronted with new problems 
tomorrow which it can not reasonably expect today. For this reason, 
the Sub-Committee plans to be flexible in its operations and in its 
viewpoint and to keep itself posted on current developments and 
needs. 

The membership of the Society can be of service to it in letting the 
industry know that there is such a Committee working for it and anx- 
ious to be of every possible assistance and ready to contribute its 
services to the national welfare. 

SUB-COMMITTEE ON SCREEN BRIGHTNESS 

Prior to the advent of the war, this Sub-Committee had been study- 
ing possible ways and means of measuring the brightness of motion 
picture screens in theaters, and had already drawn up the desired 
specifications of illumination and brightness meters necessary for 
making such measurements. Contacts had been made with instru- 
ment manufacturers in the hope that one or more of them could be in- 
duced to design such instruments and make them available to the 
motion picture field. However, with the onset of the war, these labo- 
ratories found themselves unable to cooperate in this endeavor in 
view of the more pressing demands arising from their engagement in 
war work. As a result, the Sub-Committee found itself unanimously 
of the opinion that neither development nor manufacturing facilities 
could be available for a project 'of this nature "for the duration"; 
and, furthermore, that developments resulting from the war effort 
would very probably be available after the war that would have con- 
siderable bearing on the design of the needed instruments. 

For this reason, the Sub-Committee has remained inactive during 



Feb., 1943] THEATER ENGINEERING COMMITTEE REPORT 87 

the past several months and will probably continue so until victory 

comes. 

DONALD E. HYNDMAN ALFRED N. GOLDSMITH, Chairman, 

Engineering V ice-President Theater Engineering Committee 

THEATER ENGINEERING COMMITTEE 

Sub-Committee on Projection Practice 

C. F. HORSTMAN, Chairman 

H. ANDERSON R. R. FRENCH E. R. MORIN 

T. C. BARROWS E. R. GEIB J. R. PRATER 

H. D. BEHR M. GESSIN F. H. RICHARDSON 

K. BRENKERT A. GOODMAN H. RUBIN 

F. E. CAHILL, JR. H. GRIFFIN J. J. SEFING 

C. C. DASH S. HARRIS R. O. WALKER 
A. S. DICKINSON J. J. HOPKINS V. A. WELMAN 
J. K. ELDERKIN L. B. ISAAC H. E. WHITE 

J. FRANK, JR. I. JACOBSEN A. T. WILLIAMS 

J. H. LlTTENBERG 

Theater Design Sub-Committee 

B. SCHLANGER, Chairman 

F. W. ALEXA J. FRANK, JR. E. R. MORIN 

J. R. CLARK M. M. HARE A. L. RAVEN 

D. EBERSON S. HARRIS J. J. SEFING 

C. F. HORSTMAN 

Screen Brightness Sub-Committee 

F. E. CARLSON, Chairman 
H. BARNETT W. F. LITTLE C. TUTTLE 

E. R. GEIB W. B. RAYTON H. E. WHITE 

S. HARRIS A. T. WILLIAMS 

Sub-Committee on Civilian Defense in Theaters 

H. ANDERSON, Chairman 

F. E. CARLSON S. HARRIS E. R. MORIN 
E. W. FOWLER C. F. HORSTMAN B. SCHLANGER 
J. FRANK, JR. GILBERT TYLER 



COPPER AND SULFIDE IN DEVELOPERS* 

R. M. EVANS, W. T. HANSON, AND P. K. GLASOE** 



Summary. The formation of excessive fog by a developer containing copper or 
sulfide is well known. However, no quantitative method for determining the concen- 
tration of either copper or sulfide in a developer appears to have been published. In 
this paper, polarographic methods of analysis for these substances are given together 
with photographic determinations of the effect of concentration on fog, thus demon- 
strating that the analyses are capable of determining the minimum amount of copper 
or sulfide required to cause fog under the conditions used. 

The fogging action of a developer which has accumulated sulfide by bacterial action 
is shown to be the same as that produced by afresh developer containing the equivalent 
quantity of sodium sulfide. 

I. INTRODUCTION 

In a previous communication 1 it has been shown that under a 
given set of conditions the photographic properties of a used de- 
veloper can be matched by a fresh developer made up according to 
the analysis of the used one. However, it was pointed out in that 
paper that other conditions might exist which would not be in- 
dicated by the analysis and which would cause a photographic 
effect. Such a condition may arise from the introduction into a 
developer of some substance not contained in the original developer 
or the replenisher formula. Two such impurities sometimes en- 
countered in practice are copper and sulfide, each of which produces 
fog. 2 - 3 Copper in a developer increases aerial fog, whereas sulfide 
forms fog without aeration. 

Although the action of these substances has been known for some 
time, there has been no quantitative analytical method for deter- 
mining their concentration in a developer. The purpose of this 
investigation, therefore, was to devise an analytical method for the 
concentration of copper or sulfide which causes fog and to examine 
the effect of concentration on the amount of fog produced. 

* Communication No. 883 from the Kodak Research Laboratories. Presented 
at the 1942 Fall Meeting at New York, N. Y.; received October 20, 1942. 
** Eastman Kodak Co., Rochester, N. Y. 

88 



COPPER AND SULFIDE IN DEVELOPERS 
II. COPPER 



89 



(A) Analytical. The concentration of copper in a developer 
solution can be determined very simply by means of the polarograph. 5 
A polarographic wave for copper can be obtained on the developer 
solution without any preliminary treatment. However, if some 
ethylenediamine is added to the solution, the copper wave has a 
more definite break at the lower potential and the wave height is 
about doubled. 



<oQ 
55 

so 

45 
4O 
35 
3O 
25 
20 
15 
IO 



O I 2345 6TQ9 
CC. PER LITER OF O.O4 M CUL SCXj. 

FIG. 1. Calibration curve for copper in 
developer. (Current at E = 0.70 volt vs. 
S.C.E.; sensitivity IX.) 

The analytical procedure was as follows : To 100 cc of the developer 
solution containing 10~ 5 to 10~ 3 M copper sulfate were added 2 cc 
of ethylenediamine (60%). This solution was placed on the polaro- 
graph and the current read at 0.7 volt. The sensitivity setting 
on the Fisher Elecdropode was IX. In Fig. 1 are plotted the galva- 
nometer scale readings for a series of copper concentrations. With 
this method, the copper concentration in the developer can be deter- 
mined with an accuracy of about 5 per cent. It should be noted 
that in polarographic determinations the calibration curve is ob- 
tained with known amounts of copper, or other substance to be 



90 EVANS, HANSON, AND GLASOE [J. S. M. P. E. 

determined, in a solution of composition similar to that of the solu- 
tion to be analyzed. 

(B) Photographic. Strips of 35-mm Motion Picture Positive 
Film were exposed on the lib sensitometer and then developed in a 
positive-type developer (developer formula A). Development was 
carried out by alternately immersing the film for 20 seconds and 
exposing it to air for 10 seconds. The total elapsed development time 
was 5 minutes. Developments of this kind were carried out with 
varying concentrations of copper sulfate in the developer. To 
check the aerial nature of the fog produced, developments were also 
carried out without aeration during the development in solutions 
containing copper. 

Table I (a) shows the effect of aeration during development with 
and without copper in the developer as compared to immersion 
during the whole development time. 

TABLE I (a) 

Eastman Motion Picture Positive Film 

5 Minutes Development in Formula A 
20 Seconds in Developer, 10 Seconds in Air 

0.04 M CuSO 4 
Cc. per liter Fog 



0.08 

5.0 0.08 

0.04 

5.0 1.16 



Constant 

immersion 
Intermittent 

immersion 



The same test was performed, using Eastman Fine-Grain Motion 
Picture Positive Film, with the results shown in Table I(b). 

The Eastman Fine-Grain Positive Film is very much less sus- 
ceptible to aerial fog than the regular Eastman Positive film. 

Fig. 2 shows the effect of the concentration of copper sulfate in 
the developer upon the aerial fog produced with a fixed amount 
of aeration, using Regular Motion Picture Positive and Fine-Grain 
Motion Picture Positive. 

A change in the ratio of the times of immersion and aeration also 
affected the aerial fog. With 5.0 cc of 0.04 M copper sulfate per 
liter in the developer, a fog value of 1.16 was obtained with the 
20 seconds 10-seconds condition and a value of 0.70 was obtained 
when the times of immersion and aeration were 25 seconds 5 
seconds. 



Feb., 1943] 



COPPER AND SULFIDE IN DEVELOPERS 



91 



Motion Picture Negative Film was developed in the same manner, 
with and without the addition of copper sulfate to the regular D-76 
formula. No aerial fog was obtained in either case. Motion Pic- 
ture Positive film in the same developer did not show any aerial 
fog. However, if the pH of the developer was increased, aerial fog 
was obtained. The results are shown in Fig. 3. 

As Dundon and Crab tree have shown, 4 the effect of copper in 
causing aerial fog can be eliminated by the addition of a desensitizing 
dye such as phenosafranin. With 2.0 cc per liter of a 0.1 per cent 




01 234- 56789 
CC. PER LITER OF O.O4 M Cu SO 4 

FIG. 2. Effect of copper concentration on 
aerial fog: 20 sec. in developer, 10 sec. in air, 
5 min. total time. ( Motion picture posi- 
tive; o fine-grain motion picture positive.) 

solution of the dye, the fog produced with Regular Motion Picture 
Positive film in formula A containing 8 cc of 0.04 M copper sulfate 
was reduced from 1.49 to 0.19. The addition of 4.0 cc per liter 
of the dye solution reduced the fog to 0.06. The addition of pheno- 
safranin to the copper solution did not destroy the polarographic 
wave but increased the wave height slightly. 

III. SULFIDE 

The presence of sulfide in a used developer which has been standing 
undisturbed for some time has been demonstrated by Dundon and 
Crabtree, 6 ' 7 They found that under these conditions sulfide was 



92 



EVANS, HANSON, AND GLASOE 



U. S. M. P. E. 



24 
2.2 
2.0 
1.8 
1.6 
14 
1.2 
1.0 
08 
0.6 
04 
0.2 



formed by the reducing action of bacteria on sulfite or, if some hypo 
entered into the developer, by the reduction of thiosulfate. How- 
ever, if the developer was used continuously, no sulfide accumulated 
in the solution. The effect of sulfide in a developer is the formation 
of fog or stain. Stain was formed only in a solution containing 
sulfide and a silver solvent more powerful than sulfite. In the 
presence of sodium sulfite, ordinary black fog was produced. 

The same authors showed that 

>t~ i 

the effect of sulfide could be entirely 
eliminated by adding lead acetate 
or silver nitrate to the solution or 
by the development of some film in 
the solution. 

Although these effects have been 
known, there has been no quan- 
titative method of determining the 
amount of sulfide in a developer, 
and it is not certain that the fog 
produced by a developer which 
gave a qualitative test for sulfide 
could always be attributed to the 
sulfide alone. 

(A ) A nalytical. Sulfide can also 
be determined very simply and 
rapidly by means of the polaro- 
graph. 5 In this case the dropping 
mercury electrode is the anode of 
the cell and the current has the 
opposite sign of that obtained in 
the reduction of copper. The 
polarographic wave for sulfide is 
obtained without any preliminary treatment of the developer. The 
wave starts at a potential of about 0.7 volt and is completed 
at 0.60 volt. A series of waves was made with different amounts 
of crystalline sodium sulfide, and the wave heights were plotted 
against concentration to form a calibration curve. Fig. 4 shows 
a calibration curve for the range 0-50 cc of 0.00416 M sodium sul- 
fide per liter. The wave height Vas taken as the current change be- 
tween 0.9 and 0.6 volt, measured against the saturated calomel 
electrode. 




8.5 9.0 9.5 10.0 IO.5 11.0 11.5 
pH OF D-Tfc + NaOH 

FIG. 3. Effect of H on copper 
fog. (O Motion picture negative ; 
motion picture positive.) 4.0 
Cc of 0.04 M CuSO 4 per liter; 16 
min development, 50 sec in de- 
veloper, 10 sec in air. 



Feb., 1943] 



COPPER AND SULFIDE IN DEVELOPERS 



93 



(B) Photographic. An unexposed strip of Motion Picture Posi- 
tive Film, y 4 inch by 4 inches, was developed for a definite time in 
a test tube containing 30 cc of a developer having a definite con- 
centration of sodium sulfide. Agitation was provided by inverting 
the stoppered test tube once every 2 minutes. This procedure was 
repeated for a series of concentrations of sulfide and a series of 
times from 1 to 16 minutes. The stock developer to which sulfide 



6O 



55 
50 



45 
40 



35 



3O 
25 



20 



05 IO 15 2O 25 3O 35 4O 45 5O 
CC. OF O.OO4IG M SULFIDE PER LITER 

FIG. 4. Calibration curve for sulfide in developer. 
(Current at = -0.60 volt vs. S.C.E.; sensitivity 
IX.) 



was added was made up according to Developer Formula A (Table 
lib). A 0.0416 M solution of sodium sulfide was used as the stock 
sulfide solution. Fig. 5 shows the fog density produced with vary- 
ing amounts of sodium sulfide in the developer. From these curves 
it can be seen that under these conditions a concentration of 15-20 cc 
of 0.00416 M sodium sulfide per liter is required to give fog above 
that of the developer without sulfide. From the calibration curve 
it is apparent that this amount of sulfide can be readily determined 
by the analytical method. 



94 



EVANS, HANSON, AND GLASOE 



[j. S. M. p. E. 



Since the effect of sulfide in a developer under these conditions 
has been determined, it remains to be demonstrated that the sulfide 




5 10 15 



80 85 



20 25 30 35 40 45 5O 55 GO fc5 TO 
CC. OF O.OO4IG M SULFIDE PER LITER 

FIG. 5. Effect of sulfide concentration on fog; motion picture 
positive film. 




2 4 <o 8 IO 12 14 16 18 2O 22 
DEVELOPMENT TIME (MINUTES) 

FIG. 6. Bacterial sulfide vs. sodium sulfide, 49 cc of 
0.00416 M sulfide per liter; />H 9.80. 1, Used developer; 
2, used developer + lead acetate; 3, fresh developer + 
sulfide; 4, fresh developer + sulfide + lead acetate. 

which forms in a used developer by bacterial action has the same 
effect. A used developer was allowed to stand in a stoppered bottle 



Feb., 1943] 



COPPER AND SULFIDE IN DEVELOPERS 



95 



TABLE I (ft) 

Eastman Fine-Grain Motion Picture Positive 
0.04 M CuSO* 



Cc. per liter 



5.0 

5.0 



0.04 
0.04 
0.03 
0.17 



DEVELOPER FORMULA A 

Na 2 SO 3 

Elon 

Hydroquinone 

Na 2 C0 3 

Potassium bromide 

Water to make 



Fog 

Constant 

immersion 
Intermittent 

immersion 

45.0 

1.0 

4.0 
30.0 

1.0 
1 liter 



for several weeks. It was then analyzed for sulfide, elon, hydro- 
quinone, and bromide, and the pH was measured. A fresh developer 
was then made up with these analyzed amounts plus 45 grams per 
liter of sodium sulfite and 20 grams per liter of- sodium carbonate. 



0.8 
0.6 
0.4- 

0.2 

1.6 

1.4 
1.2 
I.O 
08 
Q<o 
O.4 
0.2 



SULFIDE FOG 
SODIUM SULFIDE 
o BACTERIAL SULFIDE 




O 2 4- 6 8 IO 12 14- 16 18 2O 22 
DEVELOPMENT TIME (MINUTES) 

BACTERIAL SULFIDE vs. SODIUM SULFIDE 

FIG. 7. Bacterial sulfide vs. sodium sulfide; 175 cc of 
0.00416 M sulfide per liter; pH 9.86. 1, used developer; 
2, used developer + lead acetate; 3, fresh developer + 
sulfide; 4, fresh developer + sulfide + lead acetate. 



96 EVANS, HANSON, AND GLASCOE 

Acid was added to the fresh developer to make the pU. of the two 
developers equal. The strips were developed by the method just 
described. A calculated excess of lead acetate was added to other 
portions of the same developers and another series of strips developed 
in these sulfide-free solutions. The fog values so obtained are 
plotted in Fig. 6. The value given as sulfide fog is the difference 
between the fog obtained in the developer containing sulfide and 
that obtained in the developer after the addition of lead acetate. 
Fig. 7 shows the results of a similar experiment at a higher con- 
centration of sulfide. It is evident from these results that the 
sulfide which forms by bacterial action can be determined by analysis 
and has the same effect as added sulfide in a developer of similar 
strength. 

REFERENCES 

1 EVANS, R. M., HANSON, W. T., JR., AND GLASOE, P. K.: "Synthetic Aged 
Developers by Analysis," J. Soc. Mot. Pict. Eng., XXXVIII (Feb., 1942), p. 188. 

2 CRABTREE, J. I. : "Chemical Fog," A mer. Ann. Phot., 33 (1919), p. 20. 

3 FUCHS, E.: "Uber Schleierbildung bei der Oxydation von Entwickler- 
losungen an der Luft," Phot. Ind., 27 (1924), p. 24. 

4 DUNDON, M. L., AND CRABTREE, J. I. : "The Fogging Properties of Develop- 
ers," Trans. Soc. Mot. Pict. Eng., No. 36 (1928), p. 1096. 

6 KOLTHOFF, I. M., AND LiNGANE, J. J. : "Polarography," Interscience Pub- 
lishers, Inc., New York, N. Y. (1941). 

DUNDON, M. L., AND CRABTREE, J. I.: "Sulfide Fog by Bacteria in Motion 
Picture Developers," Trans. Soc. Mot. Pict. Eng., No. 19 (1924), p. 28. 

7 CRABTREE, J. I., AND DUNDON, M. L.: "Staining Properties of Developers," 
Trans. Soc. Mot. Pict. Eng., No. 25 (1926), p. 108. 



FACTORS AFFECTING THE ACCUMULATION OF IODIDE 
IN USED PHOTOGRAPHIC DEVELOPERS* 

R. M. EVANS, W. T. HANSON, JR., AND P. K. GLASOE** 

Summary. Development of uniformly flashed motion picture film has been 
carried out in developers of varying composition and the amount of iodide, which re- 
mains in the developer, determined by analysis. The amount of iodide has been 
found to depend on the following factors: 

(1) Developed density. Increased density gives increased iodide. 

(2} Footage of film. Increased footage for a given volume of developer gives in- 
creased iodide. 

(3) Time of development. Increased development time for the same density gives 
increased iodide. 

(4) Strength of developer. An increase in the activity of the developer gives in- 
creased iodide. 

(5) Distribution of the image. If partly unexposed film was run through the de- 
veloper the amount of iodide decreased as the proportion of unexposed film increases. 

I. INTRODUCTION 

The development of a silver bromo-iodide emulsion will introduce 
iodide as well as bromide into the developer. Dundon and Ballard 1 
showed that small amounts of iodide remained in the developer after 
development of such an emulsion, the amount of such iodide being af- 
fected by the extent of development as well as by the original iodide 
content of the emulsion. It was also demonstrated that the per cent 
of iodide in the undeveloped portion of an exposed emulsion was in- 
creased during development. This increase in iodide content of the 
emulsion was attributed to the removal by undeveloped silver bro- 
mide of iodide released during development. Evans, Hanson, and 
Glasoe 2 have shown that the amount of iodide which accumulates in a 
used developer has a significant effect on the photographic properties 
of the developer and must be determined by analysis in order to ob- 
tain the same photographic results with used and fresh developers. 
The amount of iodide found in the used developers used in these ex- 
periments was very greatly in excess of the amount to be expected 
from the solubility of silver iodide alone. This fact suggests that un- 

* Presented at the 1942 Fall Meeting at New York, N. Y.; received June 17, 
1942. Communication No. 858 from the Kodak Research Laboratories. 
** Eastman Kodak Company, Rochester, N. Y. 

97 



98 



EVANS, HANSON, AND GLASOE 



[J. S. M. P. E. 



exposed film should remove iodide from a developer and preliminary 
experiments showed that this was the case. Hence, it is evident that 
a true equilibrium is not involved any so-called equilibrium value 
obtained will simply be the result of a very particular set of conditions 

and cannot be extended to a dif- 
ferent situation. 

This experience indicated that 
the concentration of iodide re- 
maining in a developer de- 
pended on several variables, 
such as the iodide content of 
the emulsion, the developed den- 
sity, the quantity of film de- 
veloped, and the strength of 
the developer. The purpose of 
this work was to investigate 
the effect of these variables, to- 




O 20 30 40 50 fcO 70 8O 
FEET/LITER 

FIG. I. Effect of amount of film and 
density on iodide concentration. 



gether with any others which might become apparent. 

H. EXPERIMENTAL 

(A) Apparatus and Method. These experiments were performed 
on Eastman Motion Picture Negative Film which was flashed to the 
desired density on a flasher equipped with a rheostat in the lamp cir- 
cuit. The film was moved past an opening at a uniform rate by means 
of a motor drive so that the whole strip, including that outside the 
perforations, was given a uniform exposure. The intensity of the ex- 
posure was varied by means of the rheostat. 

TABLE I 

Increase in Iodide with Increasing Footage of Film (35-mm Plus-X Film; developed 

15 minutes in D-76] 

Feet of Film Cone. KI, Cone. KBr, Average 

per Liter Mg/Liter Gm/Liter Density 



10 
20 
30 
40 
60 
80 



1.9 
3.0 
3.6 
4.1 
4.5 
4.8 



0.31 
0.60 
0.78 
0.97 
1.32 
1.49 



1.02 
0.95 
0.90 
0.96 
0.80 
0.78 



The development of the flashed film was carried out on a circular 
reel of 40-ft capacity which fitted into a tank containing the devel- 
oper. The reel was rotated at a uniform rate during development. 



Feb., 1943] 



IODIDE IN USED DEVELOPERS 



The temperature was in all cases 72 F. After the development (15 
minutes in most cases) a strip of the film was fixed and dried and sev- 
eral readings of the density were made along the length of the strip. 
The average of these readings was taken as the developed density of 
the entire length of film. The density values given are densitometer 
readings from which the base density has been subtracted. The de- 
veloper was removed and analyzed for iodide by the method described 
in a previous paper. 3 



2.0 
1.8 
1.6 
1.4 
1.2 
I.O 
08 
06 
0.4 
O.Z 




1.0 



2.0 



5.0 
CKI 



4.0 
mg/LITER 



5.0 



6.0 



7.0 



FIG. 2. Effect of density at different values of footage of 
film on iodide concentration. 



10 ft/1 
20 ft/1 
30 ft/1 



40 ft/1 
60 ft/1 
80 ft/1 



The minimum volume of developer which could be used in the tank 
was 500 cc. To obtain a degree of exhaustion equal to 10 feet per 
liter, a 5-ft length of the film was developed in 500 cc of the developer. 
In a typical experiment lengths of film 5, 10, 15, 20, 30, and 40 feet 
were measured out. Each length was developed in 500 cc of fresh de- 
veloper for 15 minutes and the developer saved for analysis. A 
fresh sample of developer was used for each successive length of film 
because it was found that the strength of the developer at the start of 
development was very important in determining the final amount of 
iodide in the developer. - The results of such a typical experiment are 
given in Table I. 

(B) Effect of Developed Density and Footage of Film. Experiments 
were carried out with film which had been flashed to give varying 



100 EVANS, HANSON, AND GLASOE [j. s. M. P. E. 

densities. The curves in Fig. 1 show the increase in iodide with in- 
creasing footage of film for several densities. As one would naturally 
assume, the iodide increases with density. 

Fig. 2 is a plot of the data of Fig. 1 in which the concentration of 
potassium iodide in the developer is plotted against the density for 
varying values of feet per liter each line representing one value of 
footage. This plot indicates a linear relation between iodide and den- 
sity for a given footage of film. From this set of curves, the amount 



TABLE II 

Effect of Development Time 

Cone. KI for 

Development Cone. Same Density 

Time (Min.) Density KI (15-Min. Development) 

2 0.16 0.0 0.9 

4 0.30 0.2 1.7 

8 0.48 2.7 2.7 

16 0.85 4.6 4.7 



TABLE HI 

Effect of Increasing Footage of Film and Development Time 

Feet per Development Cone Cone. KI 

Liter Time (Min.) Density KI (15-Min. Dev.) 

10 5 0.95 0.9 1.7 

30 5 0.78 1.2 3.1 

60 5 0.71 1.9 4.0 

10 10 1.34 1.9 2.5 

30 10 1.21 4.2 4.7 

60 10 1.07 5.4 6.0 



of potassium iodide which will be obtained with a certain footage of 
film developed to a certain density can be found. 

(C) Effect of Time of Development. Four 40-ft lengths of film 
flashed to give a density of approximately 1.00 when developed for 15 
minutes were developed for 2, 4, 8, and 16 minutes, respectively. 
Curve A of Fig. 3 shows the increase of iodide with time of develop- 
ment. To determine the real effect of time of development on the 
amount of iodide the values so obtained must be compared with the 
amount of iodide which would have been obtained if the same density 
had been developed in 15 minutes. This can be done by reference to 
Fig. 2. The comparison is made in Table II. 



Feb., 1943] 



IODIDE IN USED DEVELOPERS 



101 



UJ 5.0 
h 



2.0 



1.0 



A similar experiment was carried out in which the footage per liter 
was also varied. The results are given in Table III. The last column 
gives the values of potassium iodide from Fig. 2. 

(D) Effect of Strength of the Developer. Preliminary experiments 
had shown that the amount of 
iodide in a developer was a func- 
tion of the strength of the de- 
veloper. Developers of increased 
activity were prepared by add- 
ing varying amounts of Kodalk 
to a regular D-76 developer in 
place of the borax. The film 
was given a uniform exposure, 
regardless of the developer in 
which it was to be developed. 
To produce approximately the 
same density as could be ob- 
tained in regular D-76 in 15 minutes, the time of development was 
reduced. The values of iodide given in the table under the heading 
"2.0 grams per liter of borax 15 minutes" are obtained from Fig. 2, 
using the values of density obtained in the Kodalk developer. The 
results are given in Table IV. From the results of the preceding 

TABLE IV 

Effect of Strength of Developer 




10 12 14 



8 
TIME 



FIG. 3. Effect of development time on 
iodide concentration. 






Feet 
per 
Liter 


Cone 
2.0 
Gm./Liter 
Borax 

(15 Min.) 


. KI 
5 
Gm./Liter 
Kodalk 
(10 Min.) 


Cone 
2.0 
Gm./Liter 
Borax 
(15 Min.) 


. KI 

10 
Gm./Liter 
Kodalk 

(8 Min.) 


Cone. KI 
2.0 20 
Gm./Liter Gm./Liter 
Borax Kodalk 
(15 Min.) (5 Min.) 


10 


2.5 


2.5 


2.3 


2.3 


2.0 


1.9 


20 


3.5 


3.9 


3.5 


3.6 


2.8 


3.6 


30 


4.5 


5.2 


4.5 


4.7 


3.7 


4.8 


40 


5.0 


6.1 


4.9 


6.3 


4.5 


5.7 


60 


5.7 


6.6 


5.7 


7.7 


5.1 


7.2 


80 


5.8 


7.6 


6.3 


8.6 


5.3 


8.7 



section on the effect of development time it follows that the difference 
caused by changing the developer strength would have been even 
greater if all the times of development had been the same. 

(E) Effect of Distribution of the Image. Half of the opening on the 
flasher was masked off so that just one-half of the 35-mm strip was ex- 
posed, but the exposure was increased enough to give a density ap- 



102 EVANS, HANSON, AND GLASOE [j. S. M. P. E. 

proximately twice that used for the whole strip. The procedure was 
repeated with three-fourths of the opening masked so that only one- 
fourth of the strip was exposed, but the exposure in this case was suffi- 
cient to give a density 4 times as great as that for exposure of the 
whole strip. The film flashed in this way was processed in the usual 

TABLE V 

Effect of Distribution of the Image 
(Developed for 15 minutes in D-76) 



et per 


Density Exposed 
Part 


Cone. KI 
J A Strip Exposed 
Found Calculated 


Cone. KI 
V* Strip Exposed 
Found Calculated 


10 






1.2 


0.8 


20 


1.18 




1.4 2.1 


0.9 


30 


1.12 




1.6 2.6 


1.1 


40 


1.10 


1.90 


2.4 3.1 


1.1 3.5 


60 


1.07 


1.85 


2.4 4.1 


1.0 4.4 


80 


1.09 


2.09 


2.4 5.2 


1.2 5.8 



manner. The results are given in Table V. The calculated values 
were obtained by reading from Fig. 2 the amount of potassium iodide 
which would have been obtained by one-half and one-fourth the foot- 
age of film developed to the density of the exposed portion. 

It is evident from these results that the amount of iodide in the de- 
veloper depends not on the average density of the developed strip but 
upon the relation between exposed and unexposed areas. 

TABLE VI 

Effect of Iodide in the Developer at Start of Development 
(80 feet per liter; developed 15 minutes in D-76 developer plus iodide) 

Cone, of KI 
Added to Developer Cone. KI Density 

4.8 0.80 

2.0 5.0 0.76 

4.0 4.9 0.68 

6.0 4.7 0.67 

8.0 4.7 0.66 

10.0 4.6 0.79 

(F) Effect of Iodide in the Developer at Start of Development. In 
all the preceding experiments the developer contained no iodide at the 
start of development. Forty-foot lengths of film were flashed to give 
a density of approximately 0.8 and each length developed in a devel- 
oper containing a different amount of iodide. The results are given in 
Table VI. 



Feb., 1943] 



IODIDE IN USED DEVELOPERS 



103 



The amount of iodide in the developer remains essentially constant 
when 80 feet of film per liter are run through. However, the result is 
very different when the amount of film is only 10 feet per liter. The 
results under these conditions are given in Table VII. 

(G) Removal of Iodide from a inn ^ _____ 

Developer. The results in Table 
VI indicate that when the 
amount of iodide is above a cer- 
tain value some iodide is removed 
from the developer by the film. 

An experiment was carried out 
similar to that of Table II ex- 
cept that the developer was 
made up containing 5 milli- 
grams per liter of potassium 
iodide. The results are tabu- 
lated in Table VIII and are 
shown graphically in curve B 
of Fig. 3. 

This experiment shows the removal and regeneration of the iodide 
in a developer by exposed film. The same experiment was carried out 
using unexposed film. The results are shown in Table IX and Fig. 4. 
These figures show the different rate of removal of iodide by 10 feet 
per liter and 80 feet per liter of unexposed film. 

TABLE VII 

Effect of Iodide in Developer at Start of Development 
(10 feet per liter; developed 15 minutes in D-76 plus iodide) 




FIG. 4. 



2 4 <2> 

TIME (MINI.) 

Removal of iodide by unex- 
posed film. 



Cone, of KI 
Added to D-76 

0.0 
2.0 
4.0 
6.0 
8.0 
10.0 



Cone. KI 
1.9 

2.8 
3.7 
5.0 
5.5 
6.3 



Density 

0.87 
0.71 
0.78 
0.75 
0.78 
0.87 



(H) Effect of Volume of Developer. The volume of developer was 
varied and the amount of film flashed to a given density varied pro- 
portionately so that the same number of feet per liter were developed 
in each case. The change in iodide concentration as the volume is 
varied is shown in Table X. The iodide values given are averages of 
three determinations. 



Feet per Liter 


Density 


80 


0.12 


80 


0.27 


80 


0.38 


80 


0.47 


80 


0.56 


80 


0.76 



104 EVANS, HANSON, AND GLASOE [J. S. M. P. E. 

III. DISCUSSION 

The amount of iodide which remains in a developer after the devel- 
opment of a bromo-iodide emulsion is dependent on the relative rates 
of two reactions : (1) the introduction of iodide into the developer by 

TABLE VIII 

Rate of Removal of Iodide with Exposed Film 
(Developed in D-76 -f 5 mg KI /liter] 

Development Cone. KI, 

Time (Min.) Mg/Liter 

2 1.8 

4 1.2 

6 2.0 

8 2.7 

12 4.4 

16 5.5 

development of exposed silver halide and (2) the removal of iodide 
from the developer by undeveloped silver bromide. All the fore- 
going experiments can be explained on this basis. 

TABLE IX 

Rate of Removal of Iodide by Unexposed Film 
(10 feet unexposedfilm per liter} 

Development Time (Min.) Cone. KI, Mg./Liter 

5.0 

2 4.1 

4 3.8 

8 3.0 

16 2.1 

(80 feet unexposedfilm per liter} 

5.0 10.0 

2 1.6 4.1 

4 0.6 3.3 

8 0.0 0.9 

16 0.0 0.0 

The effect of increasing developed density is simply an increase in 
reaction (1) and a decrease in reaction (2). The effect of increasing 
the footage of film is also understandable but the changing rate of in- 
crease of iodide with increasing footage for the same density (Fig. 1) 
requires further explanation. We can assume that 80 feet of film per 
liter will give 8 times as much iodide as 10 feet of the same film devel- 



f Feb., 1943] IODIDE IN USED DEVELOPERS 105 

, 

oped to the same density under the same conditions. But Fig. 4 
shows that the rate of removal of iodide with 80 feet per liter is much 
greater than that with 10 feet per liter. However, this result is not 
simply due to the increased amount of silver halide available in the 
case of the large amount of film. It must also be due to the conditions 
of agitation the chance that a given portion of the solution will come 
in contact with the film in a given time. Additional evidence for this 
' explanation is given by the data of Table X. A change in volume from 
500 cc to 1000 cc results in an increase in iodide from 2.5 to 2.9 mil- 
ligrams per liter. This increase may be the result of a decreased rate 
of removal of iodide while the rate of iodide formation remains the 
same. 

Curve B of Fig. 3 shows the rate of removal of iodide with exposed 
film. A comparison of the first part of curve B with that of curve A 

TABLE X 

Effect of Volume of Developer 
(Developed 15 minutes in D-76; density, app. 1.00} 

Volume Feet of Film Feet per Liter Cone. KI 

500 10 20 2.5 

1000 20 20 2.9 

1500 30 20 3.1 

2000 40 20 2.8 



of Fig. 4 shows the rates to be very nearly the same. This indicates 
that when exposed film is developed under the conditions given, in a 
developer containing iodide, the first reaction is the removal of a 
large part of the iodide. This reaction is then followed by the libera- 
tion of iodide from the emulsion by development according to curve A , 
Fig. 3. This fact explains the results obtained on developers contain- 
ing iodide at the start of development with different amounts of film 
(Tables VI and VII). With 80 feet per liter, the amount of iodide re- 
moved is large enough so that with the liberation of the same amount 
of iodide in each case the end value remains the same. However, with 
10 feet per liter, the amount of iodide removed is much less. The 
final concentration of iodide in the solution is the sum of that remain- 
ing plus that liberated from the emulsion. As the original amount of 
iodide in the developer increases, the amount remaining in the devel- 
oper increases, with the result that the final concentration of iodide in 
the developer is not constant. 



106 EVANS, HANSON, AND GLASOE 

The distribution of the image also affects the amount of iodide in 
the developer. The data in Table V show this to be the case. When 
40 feet of film in which one-half of the strip is exposed to a density of 
1.00 are developed, the amount of iodide should be the same as that 
obtained with 20 feet of film in which the whole strip is exposed to 
give the same density if the unexposed portion does not have any ef- 
fect. The previous experiments have shown that the unexposed film 
will greatly affect the rate of removal of iodide. The much lower 
values found with partially exposed strips can be attributed, there- 
fore, to this acceleration of the second reaction. 

The effect of increasing the strength of the developer is to increase 
the amount of iodide in the developer, as would be expected. The 
higher energy developer increases the rate of iodide formation with- 
out affecting the rate of iodide removal resulting in a higher final 
value. 

When an emulsion with low iodide content such as Eastman Mo- 
tion Picture Positive Film was used, the amounts of iodide in the de- 
veloper were in all cases too small to be considered important. The 
concentrations obtained were of the order of 0.3-0.5 milligram of po- 
tassium iodide per liter. 

REFERENCES 

1 DUNDON, M. L., AND BALLARD, A.: Brit. J. Phot., 77 (1930), p. 90. 

2 EVANS, R. M., HANSON, W. T., JR., AND GLASOE, P. K.: J. Soc. Mot. Pict. 
Eng., XXXVIII (Feb., 1942), p. 188. 

8 EVANS, R. M., HANSON, W. T., JR., AND GLASOE, P. K.: J. Soc. Mot. Pict. 
Eng., XXXVIII (Feb., 1942), p. 180. 



THE EFFECT OF DEVELOPER AGITATION ON DENSITY 
UNIFORMITY AND RATE OF DEVELOPMENT * 



C. E. IVES AND E. W. JENSEN** 

Summary. Non-uniformity of development is aggravated by short developing 
times and particularly at gammas far below gamma infinity. This non-uniformity 
can be partially overcome by agitation of the developer and a number of essentially 
different methods of developer agitation of interest in motion picture work have been 
studied experimentally. The case of continuous agitation was studied by flowing the 
developer through a conduit in which the film was located. It was found that good uni- 
formity is attainable not merely when turbulent flow is established but only when 
the intensity of turbulence is sufficiently great to reduce and make uniform the thick- 
ness of the quiescent liquid layer at the film surface. 

When agitation is of the intermittent type such as supplied by some of the present- 
day submerged jet systems or the cascade method, increased agitation is attainable 
usually by increased frequency of jet application rather than by greater liquid flow. 
Little improvement can be obtained by moderate increases in the film running speed 
or the rate of general circulation of developer in most of the present-day machine tanks. 
The agitation intensity could be increased much beyond the levels of present-day prac- 
tice but, except for a slight reduction in fog in certain cases, the effect of increased 
agitation on quality would not be significant. 

Methods of agitation are discussed in relation to the problems of application to ma- 
chine design. 






INTRODUCTION 



The effect of developer agitation upon the uniformity of develop- 
ment has been the subject of a number of papers in the field of 
general photography. In the JOURNAL OF THE SOCIETY OF MOTION 
PICTURE ENGINEERS some work on uniformity was reported by 
J. Crabtree, 1 ' 2 and J. Crabtree and J. H. Waddell. 3 The causes 
of non-uniformity are discussed in the first two papers and a bibliog- 
raphy is included in one of them. 2 Recently Clark 4 has discussed 
the general subject of agitation and uniformity. 

Causes of Uneven Development. In the ordinary process of alkaline 
development, the developer in the immediate neighborhood of a 






* Received July 22, 1942; Communication No. 868 from the Kodak Research 
Laboratories. 

** Eastman Kodak Company, Rochester, N. Y. 

107 



108 C. E. IVES AND E. W. JENSEN [J. S. M. P. E. 

developing image is rendered less active by depletion of the de- 
veloping agent, the production of soluble halides, and lowering of 
the alkalinity. Complete local exhaustion and cessation of de- 
velopment are avoided by the continuous removal of the used 
solution and replacement by fresh from the main body of the bath. 
If the rate of renewal is less than the local rate of consumption, 
development is retarded. Since the development of photographic 
images is usually arrested short of completion, the lagging areas are 
never permitted to catch up. 

Types of Unevenness. The symptoms of developer agitation 
deficiency are varied and depend upon the type of image as well as 
the arrangement of the film in the bath. When the film lies in a 
horizontal plane with the emulsion surface upward in a quiet devel- 
oper a mottled condition is usually produced. Also, development 
as a whole is retarded. If the film is allowed to remain stationary 
in a vertical plane, convection effects 5 cause streaks which are par- 
ticularly severe in areas adjacent to elements of high image density 
or to the film perforations. Very similar markings result when the 
film is moved continuously in one direction through the bath at a 
low speed as is the case in a developing machine. The Eberhard 
effect and related faults in development affecting image margins 
and sound records are usually present in some degree when agitation 
is poor. 

Present Methods of Agitation. In present-day commercial practice, 
agitation is provided in several ways with varying degrees of effective- 
ness. No agitation other than that resulting form the film motion 
is provided in certain positive developing machines but experience 
shows that this is inadequate for the more exacting types of work. 
General movement of the developer in the tank as a whole is main- 
tained in other instances by the suitable location of the discharge 
pipe from an external circulatory system. An approximately similar 
type and rate of flow has been obtained by releasing a stream of 
air or nitrogen bubbles at the bottom of the tank. A substantial 
improvement in the uniformity of sound records has been effected 
by the use of a cascade system 6 in which a large stream of developer 
is caused to flow vertically down the film strands. Other methods 
have been designed to sweep the depleted developer from the film 
surface periodically. These include the stationary squeegee used 
in a horizontal tray machine 1 and the submerged liquid jets. 3 - 7 The 
latter are used in a number of machines in varied forms. 



Feb., 1943] DEVELOPER AGITATION 109 



The presence of trailing streaks visible in some types of picture 
and of certain faults in sound records shows that the means of 
agitation employed at present are not all adequate. 

More effective agitation than is now generally used appears 
desirable for sound and picture negatives, for duplicating, and 
possibly even for positive prints. The requirements for uniformity 
are additionally severe in any operation which is followed by one 
in which a high gamma is used. Although better uniformity is to be 
expected through the use of stronger agitation, the degree of im- 
provement which can be brought about by merely speeding up the 
rate of developer circulation, for example, is obviously distinctly 
limited with some existing types of equipment. In such cases the 
means employed for agitation must be supplanted by one capable of 
greater effect. The selection of a better mode of agitation is not 
easy because of the dearth of information in a form suitable for 
ready application to existing practice. 

Scope of the Present Work. The present work was undertaken to 
obtain further information as to the relation between the degree 
of agitation and the effect upon uniformity and rate of development 
with representative types of motion picture film and, in addition, to 
determine something of the relative effectiveness of selected types 
of agitation of a practical nature. This work consists of three parts 
as follows: 

(/) Determination of the manner in which agitation must be 
changed to maintain a desired level of uniformity when the degree 
of development or the rate of development is varied. 

(II) A study of the density uniformity and rate of development 
as functions of the agitation intensity. 

(III) A comparison of the relative effectiveness of different 
ractical methods of agitation. 






PART 



Conditions Favorable to Uniformity of Development 

For the purpose of studying the interrelations between the fre- 
quency or average intensity of agitation, the time of development, 
and the completeness of development, a technique suited to small- 
scale operations was desirable. The brush method 8 was found to be 
flexible and convenient, and capable of giving reproducible results. 
The range of effective agitation intensity attainable by this method 



110 C. E. IVES AND E. W. JENSEN [J. S. M. P. E. 

was great and, as will be shown in Part III, extended above and 
below the levels of commercial practice. 

Eastman Release Positive Film Type 1301 was given a uniform 
flash exposure and then developed in one of a family of developers 
comprising a range of activity of 1 to 10 and obtained by making 
pH adjustments between 7.8 and 10.0 with a basic elon-hydro- 
quinone-sulfite formula. The rate of brushing and the total number 
of brush strokes during development were also varied widely. The 
developed samples were judged visually under critical viewing con- 
ditions against a standard of acceptability based on projection 
viewing. 

The results of these tests showed clearly that completeness of 
development (approach to gamma infinity) with corresponding in- 
crease in time of development is conducive to good uniformity even 
when the frequency of brushing is diminished so as to keep the total 
number of brush strokes for the whole period of development con- 
stant. For this reason the density uniformity of positive prints 
developed almost to gamma infinity on machines with feeble or 
infrequent agitation may be reasonably good while that of sound 
negatives on a similar type of film developed with stronger agitation 
but to a much lower gamma may be poor. 

At the shorter developing times good uniformity was obtained 
only if the frequency of agitation was increased by a factor greater 
than that by which the time was diminished. This relationship 
was found to exist whether the time of development was reduced 
to obtain a lower gamma with the same developer or to obtain the 
same gamma in less time with a developer modified to increase 
the activity. It is to be expected that uniformity will be affected 
adversely whenever the developing time is diminished whether by 
shortening the film path or by increasing the running speed in a 
particular developing machine. A desired uniformity of develop- 
ment is not assured, therefore, solely by the specification of any 
particular intensity or frequency of agitation but only when that 
agitation is appropriate for the developer and degree of develop- 
ment used. 

PART n 
The Degree of the Effect Produced by Developer Agitation 

Methods used for promoting the renewal of developer at the 
emulsion surface may be considered as falling into two principal 



Feb., 1943] DEVELOPER AGITATION 111 

classes as follows: (a) those in which dependence is placed upon 
the enforced relative motion between the emulsion and the bulk of 
the developer in a direction parallel to the emulsion surface, and 
(b) those characterized by periodic application of jets, scrapers, 
brushes, or rollers as a means of stripping or displacing the liquid 
at the emulsion surface. The first class is of interest because it 
is seldom, if ever, absent as a component of the agitation and, in 
addition, lends itself to study because it is easily specified in terms 
which are fundamental and general. The second class is of great 
practical importance but can be studied only in respect to the per- 
formance of apparatus of a particular design. 

Part II of this paper is devoted to the study of the case of con- 
tinuous flow of developer over the surface of a strip of motion picture 
film held stationary with the film support resting against the inner 
surface of a tube. 

The Criterion for the State of Flow. The literature of fluid dynamics 
provides ample demonstration that the state of flow in such a conduit 
can be determined from the value of Reynolds' criterion which is 
defined as follows : 



where Re = Reynolds number. 

D = Diameter of a tube of circular section = 4M (for tubes of any cross- 

sectional shape) . 

M = Area of cross-section of stream -f- wetted perimeter of conduit. 

V = Velocity of liquid flow. 

p = Density of liquid. 

M = Viscosity of liquid. 

The Reynolds number is a dimensionless ratio, expressing the 
relation between the magnitude of inertial forces and viscous forces 
which govern the mode of flow. Its value is the same in any self- 
consistent system of measurement. The work in this field was 
reviewed by Davies and White 9 and more recently by BakhmetefT. 10 

When the Reynolds number has a value less than 2000, the flow 
in all portions of the conduit is of the streamline or viscous type. 
At values above 2000 to 3000 streamline flow is not inherently 
stable, so that any disturbance may initiate generally turbulent 
flow conditions. When the turbulent state is attained the motion 
of various parts of the liquid passing through the conduit is dis- 
ordered and brings about considerable transverse mixing. Within 



112 



C. E. IVES AND E. W. JENSEN 



[J. S. M. P. E. 



a short distance from the conduit walls, however, the transverse 
motion is absent and the flow is of the laminar or viscous type. 
This region is .called the laminar layer. Its existence is depend- 
ent solely upon the normal viscous and inertial properties of the 
liquid and is not a result of any peculiar properties acquired in 
that region. Its thickness amounting to some thousandths of an 
inch in cases of greatest interest with this tube apparatus can be 
computed from the dimensions of the tube, the physical properties 
of the liquid, and the rate of flow. 



MOT coco 




TEMPERATURE 
- CONTROL. 

APPARATUS 



FIG. 1. Equipment for development in tube. 

The Exchange of Fresh and Exhausted Developer. The developer 
constituents must be brought into the emulsion from the main body 
of the bath and the reaction products brought out at a rate cor- 
responding to the content of a fraction of an ounce of developer for 
each linear foot of film during the period of development. This 
quantity of liquid could be moved to the general vicinity of the film 
by an almost imperceptible current in the bath. However, such a 
current would not have sufficient force to penetrate and displace 
the liquid close to the film surface. Even with more vigorous agi- 
tation such a zone exists through which chemical transfer is carried 
on mainly by the comparatively slow process of diffusion. As the 
thickness of the unstirred liquid layer increases, the rate of transfer 
becomes so slow as to limit the rate of development markedly. In 



Feb., 1943] 



DEVELOPER AGITATION 



113 



the work described below the thickness of this layer is modified as 
desired by changing the rate of flow through the conduit. 

Experimental Apparatus. The tube equipment shown in the 
diagram in Fig. 1 was used. The tube proper was made of paraffin- 
impregnated wood. As shown in the transverse section of Fig. 2, 
the bottom and top inner surfaces were provided by the base and a 
removable cover, respectively, while the vertical side walls were 
formed by the inner surfaces of the cut-out spacer. The portion of 
uniform cross-section was 60 inches in length. The film lay emulsion 
surface upward along the bottom of the tube and was held taut by 



DIMENSIONS 
OF TUBES 

CINCHES) 
a b 
x 



V* 




REGISTERING 
PIN 



/ MAXIMUM \ 

V SHOWN BY \ 
\ DOTTED LINES; 



FIG. 2. Cross-section of tube. 

ober bands stretched between the ends of the film strip and metal 
hooks set in the base (Fig. 3^4). 

The film strip was placed in the tube when the latter was empty 
of liquid and dry. Development was commenced by admitting the 
developer solution from the piping at the left end (Fig. 1) and was 
terminated by shutting off the developer supply and admitting a 
2 per cent acetic acid stop bath. 

The rate of flow of developer was determined by accumulating and 
measuring the effluent for a measured interval of time 

The densities of Kodak D-16 and D-76d developer solutions 
were approximately 1.06 and 1.1 grams per cubic centimeter and the 
viscosities about 1.3 and 1.5 centipoises, respectively. 



114 C. E. IVES AND E. W. JENSEN [J. S. M. p. E. 

Development was timed within about 2 seconds and temperature 
was held to within ==0.2F at a point near 70F. 

Effect of Flow Conditions on the Pattern of Non-Uniformity. For 
the study of the effect of different methods of using the equipment 
upon uniformity of development, it was decided on the basis of pre 
vious experience that development should be well below gamma 
infinity so that density differences would be large enough for con 
venient observation. Eastman Release Positive Film Type 1301 anc 
and Eastman Fine Grain Sound Recording Negative Film Type 1360 
were used in various preliminary tests with Kodak D-16 developer. 

It was found that the marbled or mottled effect characteristic o 
stationary development was diminished greatly with low rates o 
developer flow corresponding to Reynolds numbers below 2000 
(velocities mainly below J /2 foot a second depending on the cross 
sectional area). The shearing forces resulting from this rate of flow 
would tend to outweigh forces producing convection, etc. At the 
same time this low degree of agitation was not capable of preventing 
streaking effects. These streaks which appeared when the flow was 
in the laminar range persisted through the critical range (2000 to 
3000 Reynolds number) and then diminished steadily in severity as 
the Reynolds number increased to 40,000 or more corresponding to 
velocities upward of 3 to 9 feet a second for various tube dimensions 
The streakiness had a typical pattern and at the entrance of the tube 
appeared as shown in the Sample No. 1 of Fig. 4. The higher density 
regions in the streak or mottle patterns were interpreted as the 
location of more intense agitation or at least more rapid developer 
renewal. Variation of the size and shape of the tube cross-section 
within the limits indicated in Fig. 2 caused some change in the 
shape of the streaks but affected the severity little when comparisons 
were made at equal Reynolds numbers of 30,000 to 40,000 in the 
turbulent range. The possibility of imperfect wetting of the emul- 
sion by the developer as a cause of streakiness was eliminated by 
a test in which the film was washed in water for 4 minutes before 
the start of development. 

Use of Baffles. When disturbances are absent, it is known that the 
turbulent condition is not always attained even at Reynolds numbers 
above the critical range which is considered to be 2000 to 3000. In 
order to determine whether the streakiness resulted from the failure 
of the turbulent condition to set in or as a normal consequence 
of the existence of the thin laminar layer near the wall of the tube 



Feb., 1943] 



DEVELOPER AGITATION 



115 



a series of tests was made in which drastic steps were taken to break 
up streamline flow and thus assure the establishment of the turbu- 
lent condition. Various velocities from 0.85 to 10.3 feet a second 
extending above the critical range were used. 

The interposition of baffles at the positions indicated in Fig. 3(^4) 
caused a marked change in the pattern at the tube entrance but the 
streaks assumed their usual form about 2 feet away. However, 
it was quite evident from the effect upon the photographic density 




ENTRANCE SCREENS 

I-WOVEN WIRE MESH (ZO OR 5O MESH) 
Z- PLATE PERFORATED AT RANDOM -$<{ HOLES 
3-VERTICAL WIRE PIN SCREEN OF '/^ DIAMETER PINS 
IN Z ROWS,' SPACED V\Z CENTERS', PINS OFFSET '/: 
PINS SPACED ^CENTERS 




CROSS BAFFLES IN TUBE 

FIG. 3. Longitudinal sections of tube. 

and the shape of the streaks that the liquid motion was greatly 
altered in the vicinity of the baffles. 

A number of additional tests involved the use of cross baffles 
having various dimensions and spacing (a and b in Fig. 3C). High 
density lines transverse to the film (Example No. 2 in Fig. 4) were 
found opposite each baffle of sufficient size to interrupt the streak 
mark. Only by using the baffles at short internals throughout the 
tube could the streak pattern be suppressed entirely. 

Visual Observations. By substituting a sheet of plate glass for 
the cover of the tube it was possible to make some interesting visual 
observations of flow conditions. The liquid used for this test con- 



116 



C. E. IVES AND E. W. JENSEN 



[J. S. M. P. E. 



tained some fine suspended matter which was observed for indication 
of variation in motion in different parts of the stream. It was 
immediately apparent that the velocity of liquid movement within a 
thin layer near the glass plate was only a minute fraction of that of 
the stream as a whole. The particles in this thin layer showed little 
deviation from a relatively slow continuous forward direction even 







FIG. 4. Density unevenness patterns with tube development. 

when those in the central portion of the stream moved so fast that 
they could no longer be seen individually. 

Discussion. Although the marbled or mottled appearance char- 
acteristic of stationary development and caused by convection dis- 
appeared at low velocities in the streamline flow range, the streakiness 
which appeared in its place persisted far into the turbulent flow 
range. 

Inasmuch as the characteristic streak pattern was restored spon- 
taneously at a short distance downstream after being completely 



Feb., 1943] DEVELOPER AGITATION 117 

obliterated by the use of baffles, it must have resulted not from the 
failure to initiate the turbulent condition but from the existence 
of the thin laminar layer in which thickness variations are found 
in accordance with the geometry of the conduit and the distribution 
of stream velocity which it creates. 

At the higher rates of flow the development unevenness was 
diminished because the thickness of the laminar layer was reduced 
and made more uniform. The shearing force exerted upon the 
liquid in the laminar layer had then become so large as to dwarf 
disturbing forces and smooth out the stream velocity distribution. 

The severity of the streaks was about the same at equal Reynolds 
numbers which corresponded to velocities which varied in a ratio 
of 1 to 3 according to the dimensions of the tube. The velocity is, 
of course, not a complete specification of the intensity of the re- 
sulting agitation. 

Under the conditions of test the effects of unevenness of developer 
renewal were shown at their worst because the film was stationary. 
In a continuous developing machine the effect upon any portion of 
the film of local variations in agitation of the same degree might be 
largely erased if the film traversed a standing pattern of flow con- 
ditions which embodied sufficient diversity of arrangement. 

Although the size of elements in the density unevenness pattern 
introduced into a uniformly flashed area was usually large in these 
tests, small image elements would be affected seriously by lack of 
agitation. The size of the element of unevenness could be small, 
however, if the disturbance to flow originated from an object of 
small dimensions such as the edge of a perforation or the small 
wires of the grid (Fig. 3 location A3, and Example 4 in Fig. 4). In 
this case the average velocity was 3.35 feet a second and the Reynolds 
number 13,800 at the full cross-sectional area of the tube. The 
desired degree of uniformity of development is assured, therefore, 
not simply by the establishment of turbulent flow but only when 
the intensity of turbulence and the shearing stress are sufficiently 
great. It will be shown later that the effective intensity of agitation 
prevailing in certain practical developing machines is considerably 
greater than that corresponding to the point of transition to turbu- 
lent flow in these tests. 

Effect of Agitation on the Rate of Development. Almost without 
exception previous studies have shown an increased rate of develop- 
ment with increase in frequency or intensity of agitation. However, 



118 



C. E. IVES AND E. W. JENSEN 



[J. S. M. p. E. 



any estimate of the possible degree of increase or the manner in 
which the rate was affected by the actual availability of developer 
constituents at the film surface was not possible because of the 
complex and little understood patterns of developer motion which 
resulted from the means of agitation employed. 

A study of these relationships was therefore made with the tubular 
apparatus previously described so as to facilitate interpretation 




FIG. 5. Density-log exposure curves at various Reynolds numbers (emul- 
sion 1301). 
Emulsion: 1301 
Developer: D-16 at 70 F 
Time of dev.: l J /2 min. 
Tube section: 1 in. X 2 in. 

A Indicates 0.55 log exposure 

- Directional i low exposure upstream 
Pair \ high exposure upstream 



of the results of later tests on practical agitation. With this equip- 
ment the rate of renewal of developer at the film surface could be 
varied by changing the thickness of the laminar layer and therefore 
the length of the diffusion path. The velocity at which the de- 
veloper flowed through the tube was varied over a wide range and 
the corresponding change in thickness was calculated. Brush de- 
velopment tests were made at the same time to provide for com- 
parison with later tests of practical developing equipment. 



Feb., 1943] 



DEVELOPER AGITATION 



119 



Measurements of the growth of density and gamma with increasing 
intensity of agitation were made with four representative types of 
motion picture film as follows : 

Eastman Release Positive Film, Type 1301 

Eastman Fine-Grain Sound Recording Film, Type 1360 

Eastman Plus-^T Panchromatic Negative Film, Type 1231 

Eastman Fine-Grain Panchromatic Duplicating Negative Film, Type 1203 

This selection was made with the object of including high and low- 
contrast materials of regular and fine-grain types. These films 




O I Z 3 

BRUSH STROKES PER SECOND 

BRUSH DEVELOPMENT 
EFFECT OF AGITATION UPON DEVELOPMENT 

EMULSION-, oot 
DEVE.LOPERJ CM& 

TEMPERATURE lO'FT 
TIME OF DEV. : \ J^MINS. 

FIG. 6. Density- log exposure and density growth curves 
various rates of brushing (emulsion 1301). 



for 



were not perforated but were otherwise normal. Two developers, 
Kodak D-16 and D-76d, were used. 

Density-log exposure determinations and uniformity tests were 
made for Eastman Release Positive Film, Type 1301, in Kodak 
D-16 developer at Reynolds numbers from zero to 60,000 and by 
the brush development method through the range of zero to 4 brush 
strokes a second. With this tube the Reynolds number was 60,000 
with Kodak D-16 developer at a flow rate of 7.2 feet a second or 45 
gallons a minute. Corresponding figures for Kodak D-76d developer 



120 



C. E. IVES AND E. W. JENSEN 



[J. S. M. P. E. 



were 7.9 feet a second and 50 gallons a minute. A direct propor- 
tionality exists among these quantities so that values between zero 
and 60,000 can be obtained from the ratios given. Zero agitation 
in the case of the tube apparatus means that developer was run 
quickly into the tube and then allowed to stand without further 
movement until the completion of development. In this work 
the 1-inch by 2-inch tube section (Fig. 2) was used. 

Each test sample run in the tube equipment was made up of 
4 feet of uniformly flash exposed film to the downstream end of which 
a sensitometrically exposed strip of film was spliced. 



O-IG DEVELOPER 

TUBE DEVELOPMENT 
-X---X- BRUSH DEVELOPMENT 




0.6- 



<"0.4 

lo.z 



10 20 30 40 50 60 REYNOLDS N0./i 000 



D-76 DEVELOPER 

.!>$_, 




10 ZO 30 40 50 60 



I Z "i 4- OIZ34 

BRUSH STROKES PER SELCONO 

FIG. 7. Gamma vr. agitation with various emulsions. 

The characteristic curves for Eastman Release Positive Film, 
Type 1301, in Kodak D-16 developer developed in the tube equip- 
ment are shown in Fig. 5. Each pair of curves is for a different 
Reynolds number and all were developed for 1Y 2 minutes at 70F. 
For the sake of legibility each pair is displaced from the next by 
0.2 along the log exposure axis. 

At the right side of Fig. 6 are seen the characteristic curves pro- 
duced by the various rates of brushing. The curves are not dis- 
placed. The directional effect is entirely absent as a result of the 
alternating direction of brush movement. On the left side of Fig. 6 
the values of gamma and of density for selected exposures are plotted 
against the number of brush strokes a second. 



Feb., 1943] DEVELOPER AGITATION 121 

Data of a similar character were obtained with the other films 
and with both developers. The individual characteristic curves 
were of familiar appearance. Evidence of the directional effect 
with the tube apparatus was absent at zero velocity but appeared 
at a low rate of flow and then diminished at higher flow rates, usually 
becoming insignificant between Reynolds numbers of 30,000 and 
60,000. The growth of density and gamma with increase in agi- 
tation showed similar trends in the case of all film and developer 
combinations. It was considered sufficient, therefore, to summarize 
the results obtained in this part of the work by plotting the gammas 
obtained against the Reynolds number and the rate of brushing as 
in Fig. 7. 

The curves show that gamma and density were increased 30 to 
100 per cent by the use of strong agitation as compared to no agitation. 
The curve for brush development rose quickly at the start and then 
became practically flat while that for the Reynolds number rose 
continuously. 

The course of change in uniformity with Reynolds number was 
similar with all four types of film and much the same as reported 
in a previous section. Since the time of development chosen for 
each emulsion was that for about one-half of gamma infinity it 
seems quite reasonable that equal degrees of uniformity should be 
attained with somewhat similar intensities of agitation. 

Referring again to Figs. 5 and 7, it will be noted that with Eastman 
Release Positive Film, Type 1301, a sufficient number of datum 
points were obtained in the laminar flow range (zero to about 2500 
Reynolds number) to indicate that the rate of development did not 
change appreciably with increased rate of developer flow until 
turbulence set in. On this justification, the summary curves for 
the other emulsions were drawn to show this condition. 

The Laminar-Layer Thickness. It is desirable at this point to 
consider the laminar-layer thickness and what it means, both in 
regard to the process of chemical transfer and the power expended 
to obtain a desired degree of uniformity. When relative motion is 
maintained between the film surface and the developer as a whole, 
a force must be applied to both film and liquid to overcome the 
viscous resistance. 

Within the laminar layer a direct relation exists between this 
force and the velocity of the outer boundary of the laminar layer. 
On the assumption that the turbulent stress on one side of this 



122 



C. E. IVES AND E. W. JENSEN 



[J. S. M. P. E. 



boundary must be equal to the viscous force on the other, the thick- 
ness of the laminar layer can be computed by the following formula 
given by Bakhmeteff : 

5 N 18 
D = I5\X 

in which 5 = Laminar layer thickness in centimeters. 

N = A constant having the value of 8 when motion in every part of 
the thin layer is assumed to be strictly laminar. 

X = A friction coefficient for smooth tubes = ' Q>25 

and D and Re have the meanings given previously. The thickness calculated with 
the value of 8 for N represents the minimum. 




o.oe 



0,06 004- O.OZ O O.O8 0.06 004 

S COMPUTED THICKNESS OF LAMINAR LAYER; Cm- 

FIG. 8. Gamma vs. laminar-layer thickness. 



The data for gamma used in Fig. 7 were replotted (Fig. 8) against 
the values for laminar-layer thickness. The gamma rises as the 
thickness of the laminar layer decreases, as would be expected. 
In all cases in which the Reynolds number was not over 2500 it 
was assumed that the laminar-layer thickness was constant and equal 
to the diameter of the tube. They are represented in Fig. 8 by single 
points at the left of the break in each curve but no numerical designa- 
tion is made for them on the scale for 8. It is noteworthy that the 
very large increase in the length of the diffusion path from a value 
in the neighborhood of 0.1 centimeter to 2.5 centimeters occurring 
at the critical point (2500) produces no sharp change in gamma. 
This is explainable on the basis that the tube length is insufficient 



Feb., 1943] DEVELOPER AGITATION 123 

for the exhaustion of the developer in a layer greater than 0.1 centi- 
meter in thickness. 

From results which will be discussed in a later section the average 
agitation intensity existing in a certain practical developing machine 
is approximately equivalent to one brush stroke every 2 seconds. 
With the tubular apparatus this would correspond roughly to 25,000 
Reynolds number and a laminar layer thickness of 0.015 centimeter. 
The velocity at the outer surface of the laminar layer can be deter- 
mined from the following expression : 

- 



in which /3 = Ratio of the velocity of the surface in question to the average 

velocity in the tube. 
AT and X have the significance previously given. 

At 25,000 Reynolds number the average velocity was 93 cm. 
per second. The velocity at the outer surface of the laminar layer 
would then be 42 centimeters or 1.37 feet per second. Even if the 
effective thickness of this quiescent layer is two or three times as 
great as that computed, it is quite clear why agitation, if it is to be 
effective, must operate very close to the emulsion surface and in 
so doing must overcome considerable viscous resistance. Never- 
theless, the total power consumption expended within the laminar 
layer and the liquid in the neighborhood of the surface of 1000 
linear feet of film is surprisingly small in terms of watts. The 
comparatively large power consumption of equipment used for 
agitation is therefore an indication of low overall efficiency of power 
application. 

Time-Gamma Relationships. A series of strips was developed for 
varying times at each of two well-separated Reynolds numbers in 
the turbulent range to determine the effect upon the various sen- 
sitometric quantities. Reynolds numbers chosen were in the neigh- 
borhood of 15,000 and 75,000 and the Y 2 -inch by 1-inch tube section 
was used. The lower of these values appears to correspond ap- 
proximately to the average effective intensity of agitation employed 
in certain practical developing machines, while the higher represents 
a much greater intensity. All eight combinations of emulsion and 
developer were included. 

In general the more intense agitation accelerated density growth 
more at the shorter times of development than at the longer. The 
effect of agitation was distinctly greater with Kodak D-76d than 



124 C. E. IVES AND E. W. JENSEN [J. S. M. P. E. 

with Kodak D-16. This is probably a result of the known greater 
susceptibility of the Kodak D-76d developer to the restraining effect 
of the development reaction products. While the density and 
gamma for each time of development were generally greater for 
the higher agitation intensity, no essential change in shape of the 
characteristic curve nor in emulsion speed was found when com- 
parisons were made at equal gammas. 

The fog density was about the same at equal times of development 
with either degree of agitation. In cases where fog density was 
appreciable, a slight diminution in the fog for equal gamma usually 
resulted, therefore, with the greater degree of agitation. 

Discussion. When the time of development is such as to produce 
substantially less than gamma infinity, the degree of development 
is increased by increase in the intensity or frequency of agitation. 
By comparison with the effect of no agitation a large acceleration 
is given by a moderate degree of agitation. The additional effect 
of a further increase in agitation is less marked. 

Attempts to arrive at a satisfactory expression of the relation 
between agitation and the rate of development have not been success- 
ful, although a purely empirical expression relating the density 
growth and the laminar-layer thickness was devised. It would 
be desirable to show the manner in which the velocity constant 
of development departed from the highest value attainable as the 
laminar-layer thickness increased. However, this was not feasible 
because the determination of velocity constant is not satisfactory. 

With the type of agitation used in this part of the work the uni- 
formity and rate of development increased continuously and, at 
least in the higher ranges, in a similar way with increasing agitation. 
The rate of development of a given film in a stated developer may 
therefore be used with caution in estimating the relative ability 
of different methods of agitation to give uniform development. 

Generally speaking, improvement in uniformity parallels the 
increase in rate of development. If the average of present-day 
commercial practice corresponds to a Reynolds number of 25,000 
or less in the tubular apparatus, then a large increase in the effective- 
ness of agitation is possible and practicable. Agitation which is 
several times as intense would produce a decided effect upon uni- 
formity but would not accelerate development very much. Be- 
cause of the inefficiency of devices employed to produce agitation, 
improvement in results is obtainable only by the use of costly equip- 



Feb., 1943] DEVELOPER AGITATION 125 

ment and a substantial amount of power. An increase in the effi- 
ciency of the method of agitation is, therefore, much to be desired. 

PART III 

Practical Methods of Agitation 

It was believed possible, by the use of experimental equipment, to 
gather some useful information regarding the effectiveness of various 
types of agitation which would be applicable to the practical case 
of a continuously moving ribbon of film in the processing machine. 
In addition, some tests were made to determine the effective in- 
tensity of agitation prevailing with types of practical processing 
equipment which were known to produce a commercially acceptable 
degree of uniformity. 

The work was done at various times and involved different emul- 
sions and developers so that quantitative comparisons between 
different groups of tests are possible only through the intermediary 
of brush development tests made at the same time and with the 
same developer. 

Generally the times of development were chosen to produce 
degrees of development well below gamma infinity so that the 
attainment of complete uniformity would be difficult. Uniformly 
flash-exposed film was used for the judgment of uniformity of de- 
velopment. In statements of the number of brush strokes a second 
the quantities one-fifth, one-half, etc., represent one stroke every 
5 seconds, 2 seconds, etc. 

Movement of the Film through the Developer. The effect of variation 
of the speed of film movement was tested by the use of an experi- 
mental roller-type developing rack in which the film in a 7-ft closed 
loop was moved continuously in one direction over upper and lower 
supporting rollers. Compressed air was delivered from a number of 
orifices in metal tubes located parallel to the vertical film strands 
and separated from them by about 1 inch. 11 Film-running speeds 
through the range of 30 to 400 feet a minute were tested. 

Good uniformity was attained witli a running speed of 400 feet 
a minute. Even at this speed, however, the air agitation was an 
important factor, as is indicated by the fact that somewhat inferior 
results were obtained when the air flow was cut to one-third of 
normal. As will be shown later, the intensity of agitation pre- 
vailing under conditions approximating current practice in some 
continuous developing machines corresponds to 1 / b to 1 / 2 brush 



126 C. E. IVES AND E. W. JENSEN [J. S. M. P. E. 

strokes a second. With the single-loop roller rack a running speed 
of somewhat over 100 feet a minute corresponds to this intensity 
of agitation. 

When this rack was run at a speed of 1600 feet a minute in the 
large tank provided with general air agitation (see Roller Developing 
Rack below), good agitation equivalent to one brush stroke a seco, 1 
resulted. This running speed is not practical with existing de- 
veloping machines. 

In the cascade method of agitation of Leshing, Ingman, and Pier 
dependence is placed largely upon the high relative velocity of the 
film and the downward flowing stream of developer. In a 6-fo 
height the average velocity must be somewhat less than the 10-foot- 
a-second rate which would apply to the case of a freely falling body. 

Roller Developing Rack. A test was made of the equivalent 
agitation intensity produced by the roller developing rack of 200-ft 
capacity described in a previous paper. 12 This rack was operated 
at a film running speed of 140 feet a minute. General agitation 
of the developer in the 120-gallon tank was provided by com- 
pressed air jets at various points along the bottom. These operating 
conditions were such as to produce commercially acceptable uni- 
formity in various types of motion picture work. The equivalent 
brush agitation was found to be about one stroke every 5 seconds. 

Vertical Rack-Type Developing Machine. A determination was 
made of the degree of agitation attained in a vertical rack-type 
continuous developing machine relative to frequency of brushing. 
The machine was designed for low operating speeds (20 to 30 feet 
a minute) and dependence was placed on vigorous air agitation to 
obtain uniformity of development. A commercially usable degi 
of uniformity of development was obtained in the normal processr 
of various types of motion picture film under these conditions. The 
intensity of agitation was found to be equivalent to somewhat more 
than one brush stroke every 5 seconds. 

Roller Wringers. The use of pressure rollers for forcibly bringing 
about the replacement of developer at the photographic emulsion 
was tested in the following manner: A loop of film approximate!' 
12V 2 inches long was mounted so that it ran between a pair of 2- 
inch diameter rotating soft rubber wringer rollers which pressed to- 
gether. The axes of the rollers and film loops were vertical. 

This method was very effective, causing a higher rate of de- 
velopment than the brush method when equal numbers of passes 



Feb., 1943] 



DEVELOPER AGITATION 



127 



in a second were made. Although the effect of the running speed 
of the film could not be separated it was evident from the results 
of subsequent work that it must have contributed only in a minor 
degree. 



ton* 



PRESSURE: 

MEASURING 



MOVEMENT 
OF FILM 



ANGLE OF JET 
IMPINGEMENT 
ADJUSTMENT 




NOZZLE 
FILM 



C TEMPERATURE. 

CONTROL APPARATUS 



PRESSURE MEASURING APPARATUS 
'GLASS TUBE OR BOURDON GAUGE 



CROCK 



DEVELOPER 
LEVEL 




LENGTH OF 
ADJUSTMENT 



TEMPERATURE 
CONTROL, ' 
APPARATUS 



PUMP 



FIG. 9. Equipment for jet agitation tests. 



Scrapers and Wipers. Stationary wiping devices in contact with 
the emulsion surfaces were tried for this purpose but scratching, 
'.''psening of the emulsion, or longitudinal lines of differing density 
resulting from irregularities in the wiper were always encountered, 
making the scheme unsatisfactory. 

Submerged Jets. At the present time considerable use is being 
made of submerged jet agitators, 3 located so that each part of the 
moving film strip passes a jet at intervals of a few seconds or less. 






128 C. E. IVES AND E. W. JENSEN [J. S. M. P. E. 

The nozzles are close to the film and are intended to produce a 
strong local effect without causing rapid general stirring of the bath. 

Some tests have been made to determine the intensity of agitation 
obtainable by the use of submerged jets in comparison with brush 
development. The equipment used is shown in Fig. 9. The film 
was held under tension on a drum about 6 inches in diameter and 
! 3 /4 inches thick. Developer was supplied by a pump through a 
pipe equipped with a throttle valve. 

Drill-Hole Jets. The drill-hole type nozzle which has been used 
in several recently built developing machines was chosen for this 
work. It consisted of a stainless steel tube of 1 /2-inch inside and 








I 






456 
FIG. 10. Density unevenness patterns with jet development. 

5 /8-inch outside diameter in which four 0.039-inch diameter drill 
holes were placed at l /4-inch center distances in a line along one 
side parallel to the axis. The tube was positioned with the row of 
holes transverse to the film strip. In the following account it 
will be understood that the angle of impingement was 90 degrees to 
the film surface except where otherwise stated. 

Film Stationary. Application of these jets caused a large ac- 
celeration of development relative to the results obtained without 
agitation. With the film stationary the effect of variation of jet 
velocity from 8 to 35 feet a second and of jet length from l / u to 
1 inch upon the density of the film directly in front of the jets was 
small. 

Example No. 1 in Fig. 10 shows the pattern produced at Vie-mch 



Feb., 1943] DEVELOPER AGITATION 129 

distance and an 8-foot-a-second flow rate. It is evident that under 
these conditions the effects of agitation were confined to a small 
area. For this jet velocity the density at 3 x /2 inches distance from 
the axis was no greater than as if the jets were not operated. As 
the jet length increased, the area benefiting from agitation was 
also increased, as shown in Examples Nos. 2 and 3. In these il- 
lustrations the point of impact of the jet was approximately as 
indicated by the inked lines at the right of each example. Inter- 
ference between the currents of developer mushrooming out from 
the point of impact of adjacent streams caused the peculiar lines 
halfway between. At the highest velocities tested the effect of the 
agitation extended to a considerable distance from the point of 
impingement. For the purpose of illustration the contrast of the 
examples in the figure has been increased greatly. 

Film in Motion. Another series of tests was made to study the 
effect of rotating the drum so as to cause each portion of the film 
strip to pass the line of jets once every second (60 rpm) or once 
every 2 seconds (30 rpm). Various jet velocities up to 35 feet a 
second were used in each case with a jet length of V* inch. When 
no jets were used, the effect of rotating the drum was to accelerate 
development to a degree equivalent to a little less than one brush 
stroke every 5 seconds. The film had the unevenness pattern 
shown by Example 5 of Fig. 10. Further acceleration of develop- 
ment by the action of the jets was obtained with each increase in 
jet velocity up to the highest velocity tested, 35 feet a second. The 
highest rate of development attained was equivalent to 1 to 2 brush 
strokes a second and, therefore, much less than that produced with 
continuous application of the jets. 

Example No. 4 in Fig. 10 shows the effect obtained in some of the 
tests when the drum was rotated. The cause of this pattern is the 
same as in the case of Examples Nos. 1 and 3 but the lines are straight 
and extended because of the movement of the film past the jet. 
With the higher jet velocities the prominence of the lines diminished. 
This serious type of marking would occur in a developing machine 
if the jets at all nozzles were in identical positions relative to the 
width of the film. It would be avoided if the nozzles were sufficiently 
great in number and in varied positions relative to the film. Dif- 
ferences in spacing or inclination of the drill holes or the presence 
of small irregular transverse motions of nozzle or film strip would 
likewise be beneficial. 






130 C. E. IVES AND E. W. JENSEN [J. S. M. p. E. 

With a sufficiently high jet velocity such as 35 feet a second it 
was possible to vary the distance from the nozzle to the film from 
V 4 inch to 1 inch and the direction from the perpendicular to a line 
tangent to the film as it lay against the cylindrical surface without 
much change in the effectiveness of the treatment. When the axis 
of the jet was tangent to a circle x /4 inch outside that occupied by 
the film, the effectiveness fell off in a marked degree, indicating that 
the jet had not widened out greatly at this one-inch distance from 
the nozzle. Direct confirmation of this was obtained by exploring 
the field around the path of one of the submerged jets with a length 
of hypodermic needle tubing connected to a manometer. It was 
found that although the jet increased in width at a distance from the 
nozzle, the force within a circle of a few times the original diameter 
was well conserved at distances of about one inch. Thus with a 
nozzle velocity of only 7 feet a second the principal stream was 
confined to a circle of about 3 / 8 -inch diameter at a distance of ! 3 / 8 
inches from the nozzle. 

The direction of movement of the film relative to that of the 
developer in the jet, as when the jet struck the film at grazing in- 
cidence, made no difference, obviously because the velocity in the 
jets was high relative to that of the film. 

Roller Developing Rack with Submerged Jets. The effectiveness 
of agitation given by a roller developing rack equipped with sub- 
merged jet agitation provided by the drill-hole nozzles was tested. 
The drill holes were 0.060 inch in diameter and were spaced 5 /ie inch 
apart so that four covered the width of the film. The running 
speed of the film was about 200 feet a minute. 

The effect of the film motion without the use of the jets was 
equivalent to 3 brush strokes every 4 seconds. This rather strong 
agitation probably results from the arrangement of the film path 
in two parallel racks in a narrow tank which must tend to suppress 
general movement of the developer with the film by bringing the 
streams set up by nearby film strands into opposition. With a nozzle 
pressure of about 5 pounds per square inch corresponding to 27 feet 
a second velocity, tests were made with different spacings between 
successive nozzle tubes. 

It was found that the effect of the agitation given when the film 
passed either one or two rows of jets a second was equal to that 
given by an equal number of brush strokes a second. Two brush 
strokes a second, of course, represents a rather vigorous agitation. 



Feb., 1943] DEVELOPER AGITATION 131 

At two passes a second the effect of increasing or decreasing the 
pressure in the jets by a factor of two had only a minor effect. Pres- 
sures of a few pounds per square inch are considered practical and 
higher pressures appear to be unnecessary. 

Jets in Air. A few experiments were made using the drill-hole 
type of orifice to direct streams of developer through the air to a 
strip of film mounted on the drum mentioned above. When the 
film was held stationary the development rate was about as high 
relative to brush development as in the similar case with submerged 
jets. However, the flashed film showed the continuous line jet 
patterns or streakiness or both under all conditions tested. Fre- 
quencies of application up to twice a second and jet velocities up to 
27 feet a second were used. Unevenness was worse than expected 
apparently because there was time between successive applications 
of the jets for the developer to run off. A spray reaching all parts 
of the film frequently should therefore be better. 

Discussion. Although a 500 to 1000-ft-a-minute film running speed 
or a corresponding rate of flow of the bulk of the developer along 
the film surface provide strong agitation, they are not the most 
suitable means for application to developing machines of the usual 
type. A preferable arrangement is to maintain this rate of motion 
in a region of comparatively small thickness of the developer near 
the film surface. The only existing case of this kind appears to 
be in the cascade method previously mentioned. 6 

Essentially different and more suited to general use are the methods 
in which the developer is pushed away from the film surface and 
replaced periodically, for example, by means of submerged jets, 
wringers, and scrapers. 

Submerged jets are highly effective in accelerating development 
and when applied properly should provide almost any desired degree 
of uniformity of development. For distances under one inch, the 
effectiveness of the jets is not altered greatly by distance or angular 
disposition. Periodic application, while somewhat less effective 
than continuous, produces a strong agitation which is comparable 
with an equal number of brush strokes in unit time. The use of 
the spaced drill-hole type of nozzle with appropriate velocity should 
be equally as effective as a slit type if a sufficient number of jets are 
used and if their positions relative to the width of the film are varied. 
That perfectly uniform distribution of flow is not assured by the 
use of a slit-type nozzle is shown by .Example No. 6 in Fig. 10 which 






132 C. E. IVES AND E. W. JENSEN [J. S. M. P. E. 

was developed while being held stationary in the jet issuing from a 
slit 1.55 inches long by 0.035 inch wide. The use of the spaced 
drill-hole nozzle permits the use of higher pressures than the slit with 
economical rates of pumping. 

The foregoing account would indicate that the spacing between 
drill holes and the size of the holes is not highly critical, the principal 
requirement being that a sufficient quantity of developer be de- 
livered with moderate force at all of the nozzles. With the drill- 
hole nozzles such as were used in these tests it would appear desirable 
to use supply pressures of only a few pounds per square inch or a 
jet velocity of 10 to 30 feet a second with a frequency of application 
of once a second. This should assure results above the average 
of present practice. It is believed that a frequency several times 
as great would be necessary to make any great reduction in image 
edge effects particularly when development is carried to less than 
one-half of gamma infinity. 

Submerged jets and wringers are highly effective because they 
penetrate the liquid near the emulsion surface. It is considered 
probable that the wringer produces the maximum possible effect 
at each contact but it was found in this work that the jets approach 
this limit rather closely. The total effect obtained with either is 
dependent mainly upon the frequency of application. With film 
running speeds of 100 and more feet a minute there is space along the 
length of the film for application of jets, wringers, or other wipers 
as often as 5 times or more a second. 

There would be danger of damage to the film surface if wringers 
came in contact with the film. Therefore a scraper or roller would 
be preferable which was close to the film surface without making 
contact with it. At higher film running speeds now used a scraper 
design might be adopted which would be more effective than those 
used up to the present. 1 

The use of submerged jets at short intervals would require large 
pumps and more piping than there is space for in existing machines. 
In a new design efficiency might be improved by eliminating the 
external circulating system. In fact, the circulatory path might 
even be confined to a space within a few inches of the point of jet 
application. 

The use of jets in air as in spray development undoubtedly has 
great potentialities but must await further study. 





. 

Feb., 1943] DEVELOPER AGITATION 133 

SUMMARY 

(1) Non-uniformity of development is caused by local accumu- 
lations of partially exhausted developer in or at the surface of a 
photographic emulsion. 

(2) Conditions favorable to good uniformity are : 

(a) Full development, i. e., approach to gamma infinity. This 
permits those areas which may have lagged during the more rapid 
stage of development to catch up. 

(b) The use of developers which work slowly enough to provide 
ample time for renewal of exhausted developer at the emulsion 
surface. 

(c) The use, where possible, of developers which undergo com- 
paratively little change in activity with use. 

(d) Vigorous random agitation so that the exhausted developer 
is removed forcefully and rapidly. 

(3) Developer renewal is promoted by strong turbulence in the 
developer moving along the emulsion surface but the mere existence 
of mild turbulence is not sufficient. However, with adequate in- 
tensity of turbulence the thickness of the residual thin liquid layer 
moving over the emulsion surface in a state of laminar flow is re- 
duced and made more uniform. The forces which operate to bring 
this about tend to dwarf the forces of convection, etc., which other- 
wise would cause non-uniformity. 

(4) Intermittent methods of agitating such as those involving 
the use of wipers, wringers, and jets operate to limit the accumulation 
of exhausted developer by periodically diminishing the thickness 
of the quiescent liquid layer and are very effective if the application 
is sufficiently frequent. The frequency probably should be upward 
of once a second depending upon the uniformity required and the 
difficulty imposed by the other factors. 

(5) With submerged jets of the type which consists of small 
drill holes in rows lying transverse to the film, the effective agitation 
can be increased more by increasing the number of groups of jets 
passed by the film in unit time than by an increase in jet velocity 
beyond 20 feet a second. 

(6) The effectiveness of submerged jets (drill-hole type) is not 
paired very much by change in distance from nozzle to film under 

one inch nor when the velocity is fairly high, as, for example, 35 
feet a second, by change in angle of impingement. The size and 






134 C. E. IVES AND E. W. JENSEN [J. S. M. p. E. 

spacing of the drill holes is probably not very critical as long as the 
position of the points of impact with the film is not too regular. 

(7) On the whole, the degree of agitation employed on existing 
developing machines is quite low in comparison with that which is 
desirable and readily attainable. 

(8) An increase in running speed over the present 75 to 200 feet 
a minute would have to be large to produce in itself a significant 
improvement in agitation. 

(9) Both the uniformity and the rate of development increase 
continuously with increase in the degree of agitation. A difference 
in rate of development under some conditions indicates a correspond- 
ing difference in the ability to give uniform development. 

(10) The means employed for increasing agitation can in itself 
cause unevenness in the form of lengthwise lines if it is not applied 
to all portions of the film in an equal degree. 

(11) Increased agitation beyond good present-day levels causes 
no significant change in emulsion speed or shape of the characteristic 
curve. However, strong agitation accelerates image growth more 
than fog growth so that a reduction of fog for a constant gamma 
often results. 

(12) Development is retarded to a greater extent with Kodak 
D~76d developer than with Kodak D-16, when agitation is inade- 
quate. 

(13) Although particular attention was not devoted to the effect 
of agitation on image edge effects, it is to be expected that improved 
agitation will have its beneficial effect here as well. 

(14) Rather similar trends in the effects of agitation must be 
expected in other processes such as fixing and washing. 

PRACTICAL RECOMMENDATIONS 

While relatively complete development is favorable to the at- 
tainment of uniformity, the gamma to be used is determined ordi- 
narily by other considerations. However, some advantage can be 
gained by avoiding developers which work too rapidly. 

In the development of positive film in most laboratories the only 
agitation is that which results from the motion of the film and, to 
a lesser degree, from the bulk movement of the developer in the 
tank. The agitation is rather feeble but serves the purpose because 
the requirements for positive film are less severe than for negative. 



Feb., 1943] DEVELOPER AGITATION 135 

More pains are taken to provide agitation in negative develop- 
ment. From one-half to three-quarters of the negative developing 
machines in use today are equipped with some type of "turbula- 
tion" system by which small jets of developer are directed against 
the surface of the film at intervals varying in different machines 
from a few inches to several feet along the film path. There are 
substantial differences in the size and arrangement of the orifices. 
In most of these machines increased agitation could be obtained 
effectively by increasing the frequency at which the film passes 
the jets, that is, by installing more jets so that they are closer to- 
gether. 

Little improvement is to be expected from any practicable in- 
crease in the general circulation of the developer in machine tanks 
of the usual size and proportions. The use of compressed air or 
other gases for agitation appears to be about as effective as existing 
installations of some of the other methods but is definitely limited 
in its effect. Air agitation has never been used very extensively. . 

Increasing the film running speed by a factor of less than 4 or 5 
times would not, in most cases, have any large effect unless the 
motion of the developer concurrently with the film surface could 
be interrupted frequently by a wiper, squeegee, or wringer. Station- 
ary rubber squeegee blades at intervals of 6 inches along the film 
path have been used with good effect in a horizontal-tray type of 
machine but neither the squeegee nor this type of machine is in 
wide use at present. 

A recently published paper on the cascade method 6 showed that 
it was a substantial improvement over current practice but the 
authors of that paper felt that there was need for further improve- 
ment. Any increase in the effectiveness of this scheme would re- 
quire more frequent application of the cascade. This might entail 
changes in the size of both the rack and the tank. 

When it is attempted to increase the effectiveness of the agitation 
in either the jet or cascade method, difficulties may be met in the 
matter of supporting the film against the applied pressure, and in dis- 
posing of the necessary additional piping and nozzles. For these 
reasons it would appear desirable to devote some attention to means 
of agitation which could be located in the machine tanks near to the 
film so as to eliminate the cumbersome pumping and distributing 
systems. 

Any change in the method of agitation which causes an increase 



136 C. E. IVES AND E. W. JENSEN 

in the rate of development usually effects an improvement in the 
uniformity but the change from very poor to intense agitation 
increases the development rate by a factor of no more than 2 in 
most practical cases. 

REFERENCES - 

1 CRABTREE, J.: "Directional Effects in Continuous Film Processing," J. 
Soc. Mot. Pict. Eng., XVIII (Feb., 1932), p. 207. 

2 CRABTREE, J.: "Uniformity in Photographic Development," J. Soc. Mot. 
Pict. Eng., XXV (Dec., 1935), p. 512. 

3 CRABTREE, J., AND WADDELL, J. H.: "Directional Effects in Sound-Film 
Processing II," /. Soc. Mot. Pict. Eng., XXI (Nov., 1933), p. 351. 

4 CLARK, WALTER: "The Technique of Uniform Development," Phot. Tech. 
(Oct., 1940), p. 54. 

6 BULLOCK, E. R. : "On Convection Effects in Photographic Bathing Opera- 
tions in Absence of Agitation," Amer. Phot., 16 (March, 1922), p. 162. 

6 LESHING, M., INGMAN, T., AND PIER, K. : "Reduction of Development 
Sprocket-Hole Modulation," J. Soc. Mot. Pict. Eng., XXXVI (May, 1941), p. 
475. 

7 BEST, G. M., AND GAGE, F. R.: "A Modern Studio Laboratory," J. Soc. 
Mot. Pict. Eng., XXXV (Sept., 1940), p. 294. 

8 CLARK, W.: "Standard Development," Phot. J. (New Series), 49 (Feb., 
1925), p. 76. 

9 DAVIES, S. J., AND WHITE, C. M.: "A Review of Flow in Pipes and Chan- 
nels," Engineering, 128 (July 19, 1929), p. 69; Ibid., 128 (July 26, 1929), p. 98; 
Ibid., 128 (Aug. 2, 1929), p. 131. 

10 BAKHMETEFF, B. A.: "The Mechanics of Turbulent Flow," Princeton 
University Press, 1936. 

11 IVES, C. E., AND KUNZ, C. J. : "Solution Agitation by Means of Compressed 
Air," /. Soc. Mot. Pict. Eng., XXXIV (April, 1940), p. 364. 

12 IVES, C. E. : "An Improved Roller-Type Developing Rack with Stationary 
Drive," /. Soc. Mot. Pict. Eng., XXXI (Oct., 1938), p. 393. 



SOCIETY ANNOUNCEMENTS 

SMPE RECOMMEND PRACTICE FOR 16-MM MOTION PICTURE FILM 
EDGE-NUMBERING INTERVAL 



In the May, 1942, issue of the JOURNAL on page 426, was published the SMPE 
Recommended Practice for Edge-Numbering 16-Mm Motion Picture Film, read- 
ing as follows : 

If 16-mm film is edge-numbered, the interval between consecutive footage numbers 
shall be 40 frames. 

This Recommended Practice was approved by the Standards Committee prior 
to publication, and one of the purposes of such publication is to invite comments 
on the Committee's actions from readers of the JOURNAL. 

At the time of formulation of this Recommended Practice, the industry was 
canvassed by a sub-committee of the Standards Committee and the preponder- 
ance of opinion appeared at that time to favor the 4-frame interval. 

Since that time, however, a paper by H. A. Witt, published in the July, 1942, 
issue of the JOURNAL (p. 67) has presented arguments in favor of establishing the 
16-frame interval as the basis for edge-numbering, particularly from the point of 
view of the film editors, who are the ones most concerned with edge-numbering. 

The entire question was carefully reviewed by the Standards Committee and a 
number of opinions were expressed for 40-frame interval. It was also pointed out 
that only one film manufacturing company was set up at the present time to edge- 
number 16-mm film. 

As a result of the discussion, the Committee voted to retain in its present form 
the Recommended Practice quoted above, but that an expression of opinion be 
asked from the trade through the medium of the JOURNAL. It is for such purpose 
that this announcement is published, and all interested readers of the JOURNAL 
are urged to send their opinions to Mr. D. B. Joy, Chairman of the Standards 
Committee, addressed to the office of the Society at the Hotel Pennsylvania, New 
York, N. Y. 



137 



MEMBERS OF THE SOCIETY 

LOST IN THE SERVICE OF 

THEIR COUNTRY 



FRANKLIN C. GILBERT 
ISRAEL H. TILLES 






JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

VOLUME XL MARCH, 1943 



CONTENTS 

PAGE 

The Variable-Density Film-Recording System Used 
at MGM Studios " J. K. MILLIARD 143 

Maintaining Projection Standards in War Time 

L. B. ISAAC 176 

The Focusing View-Finder in Television Camera 

G. L. BEERS 181 

Fifty-Third Semi-Annual Meeting, Hotel Pennsyl- 
vania, New York, N. Y., May 4th, 5th, and 6th 197 



(The Society is not responsible for statements of authors.) 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

SYLVAN HARRIS, EDITOR 
ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH, ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
** President: HERBERT GRIFFIN, 

90 Gold Street, New York, N. Y. 
*' 'Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
** Executive Vice-President: -LOREN L. RYDER, 
5451 Marathon Street, Hollywood, Calif. 
^Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Avenue, New York, N. Y. 
**Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 
* Financial Vice-President: ARTHUR S. DICKINSON, 

28 W. 44th Street, New York, N. Y. 
** Convention Vice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
^Secretary: E. ALLAN WILLIFORD, 

30 E. 42nd Street, New York, N. Y. 
^Treasurer: M. R. BOYER, 

350 Fifth Ave., New York, N. Y. 
Governors 

*H. D. BRADBURY, 411 Fifth Avenue, New York, N. Y. 
*FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*ALFRED N. GOLDSMITH, 580 Fifth Avenue, New York, N. Y. 
*A. M. GUNDELFINGER, 2800 S. Olive St., Burbank, Calif. 
*CHARLES W. HANDLEY, 1960 W. 84th Street, Los Angeles, Calif. 
*EDWARD M. HONAN, 6601 Romaine Street, Hollywood, Calif. 
*JOHN A. MAURER, 117 E. 24th Street, New York, N. Y. 
**WILLIAM A. MUELLER, Burbank, Calif. 

*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
**H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**JOSEPH H. SPRAY, 1277 E. 14th Street, Brooklyn, N. Y. 
**REEVE O. STROCK, 195 Broadway, New York, N. Y. 

*Term expires December 31, 1943. 
**Term expires December 31, 1944. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motion 
Picture Engineers, Inc., 20th and Northampton Sts., Easton, Pa., or Hotel Pennsylvania, New 
York, N. Y 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1943, by the Society of Motion 

Pictuie Engineers, Inc. 



THE VARIABLE-DENSITY FILM-RECORDING SYSTEM 
USED AT MGM STUDIOS* 



JOHN K. BILLIARD** 

Summary. This presentation is a discussion of the complete variable-density 
recording system used by Metro-Goldwyn- Mayer Studios. 

The channel is the result of several years of development and engineering to achieve 
a high standard of quality and signal-to-noise ratio. The complete system is de- 
scribed, beginning with the microphone, limiter amplifier, R.M.A. pre- and post- 
equalization, improved coils with special shielding, cylinder lens, noise reduction, 
improved type headset monitor, fine-grain film sensitometry, improved super- 
portable equipment, new recording machines and re-recording machines, and disk 
recording apparatus. Engineering specifications and analysis of the design con- 
siderations and the functional aspects of the apparatus are given. 

The more general principles used in the application of variable- 
density sound-film recording have been widely published. However, 
many special features connected with the design and use of such a 
system have not had industry-wide application. This paper con- 
cerns these special features. 

Some of these improvements have only recently become available 
and practicable and it is these that have contributed considerably to 
the better overall technique. Among the most responsible have 
been the material reduction of intermodulation throughout the 
system; 1 particularly in the modulator fine-grain film; microphones; 
methods of limiting the peak value of the signal by a limiter amplifier; 
peak-operated noise-reduction units; peak reading volume indicators; 
pre- and post-equalization ; improvements in the film-running motion ; 
a new type of monitor headset; neutralization of light-valve reso- 
nance effects; and the utilization of amplifiers using special trans- 
formers and equalizers. 



* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received June 
1, 1942. 

** Metro-Goldwyn-Mayer Studios, Culver City, Calif. 

143 



144 



J. K. HlLLIARD 



[J. S. M. P. E. 



Up to the present time many types of pressure and velocity- 
operated microphones have been used, with continually increasing 
quality. With the availability of the cardioid type of microphone 
several improvements in pick-up technique have been made possible. 
One of the principal advantages of this type of microphone is the 
reduction of background noise due to cameras, perambulators, arcs, 
and general stage noises. In addition, the present unit incorporates 





FIG. 1. Cardioid microphone. 



FIG. 2. 



Cardioid microphone suspen- 
sion mounting. 



a smoothness of response and a freedom from change of frequency 
characteristic that were not possible with other units. At the same 
time an adjustment has been provided for changing the shape of the 
microphone pattern at will, where extreme acoustical conditions de- 
mand a distribution pattern differing from the cardioid. The use of 
steps between the true cardioid and straight ribbon pattern enables 
the mixer to minimize unwanted directional reflections. As an ex- 
ample, it is possible to use a step nearer the ribbon pattern for reduc- 
ing the reflections from a table-top or the "boomy" conditions in a 
taxicab shot or in a very small three-walled set with close parallel 
side- walls. 

The particular cardioid microphone that is used, known as the 
RA-1142 microphone, is an adaptation of the 639 type 2 (Fig. 1). 



Mar., 1943] FiLM-RECORDING SYSTEM 145 

Several changes were made so as to obtain a smoother frequency 
characteristic from the pressure-operated unit and reduce the baffle 
effect of the outer case. The unit has a four-point Lord suspension 
mounting between the outer oval case and the actual ribbon and 
pressure units, so that boom noises and general vibration of the case 
do not contribute to noise in the recorded sound (Fig. 2). The case is 
somewhat farther from the unit, which helps to reduce wind noise. 
The outer case is made of perforated steel, which contributes to 
mechanical strength and at the same time provides a magnetic screen 




FIG. 3. Two-stage microphone amplifier. 

for iron filings. This has entirely reduced the iron-filing pick-up 
trouble as compared with the non-magnetic case. This change alone 
has made this type of unit practicable, as iron filings have been a 
great cause of maintenance and delay before the use of this new case. 

The output of the microphone is transmitted to a two-stage ampli- 
fier having a gain of approximately 55 db, and is housed in a small 
oblong box at the base of the boom. This amplifier has transformers 
with approximately 90 db of magnetic shielding (Fig. 3) . Its stability 
is improved by the use of feedback, and its carrying capacity is such 
as to allow a 30-db margin between its average transmission level and 
its overload point. 

A two-position mixer is provided and the output of this unit is fed 
into a microphone equalizer (Fig. 4). Step 1 is the normal music 
equalization, and steps 2 to 5 incorporate the various degrees of dialog 



146 



J. K. MILLIARD 



[J. S. M. P. E. 



effort equalization that have been found necessary. The output of 
this equalizer is then amplified by a single-stage amplifier which 
raises the signal to a sufficient level so that it may be transmitted 
over a considerable distance to the main recording unit. In this main 
unit a 60-db maximum gain limiting amplifier is utilized to drive the 
modulator and its auxiliary apparatus, such as the volume indicator, 
noise reduction, monitor, disk recording machines and spare bridging 
amplifiers. Fig. 5 is a diagram of the overall complete recording 
channel as it is now being used. 

The improvement in quality achieved with this microphone and 
other channel improvements made overmodulation of the light-valve 
very noticeable, and a limiting amplifier was incorporated to reduce 
this form of distortion. 




FIG. 4. Cardioid microphone equalizer. 

In the recording of sound, the volume varies momentarily over a 
wide range of intensity. In order that this intensity range may be 
sufficiently modified so as to fit the range of the recording medium, it 
has been necessary to limit the peaks manually. In music and speech 
the peak voltage used to modulate the recorder is at least 8 to 10 db 
higher than tjie values indicated by the average volume indicator, 
because the average volume indicator calibration is correct only for 
sine waves. For this reason it has been necessary to set the volume 
indicator 8 to 10 db below the overload point to allow for this de- 
parture from the sinusoidal form. Also, for no distortion at the peaks, 
at least 10 db more carrying capacity must be available to drive the 
modulator than the sine- wave testing signal indicates. 

In order to keep the signal-to-noise ratio as high as possible, occa- 
sional overmodulation, while infrequent, may, nevertheless, cause 



Mar., 1943] 



FILM-RECORDING SYSTEM 



147 



objectionable distortion to experienced observers. By providing an 
amplifier that will reduce the volume range automatically, certain 
definite improvements in quality and noise reduction can be achieved. 
The usual method involves the reaction time of the mixer operator, 
and even though he may be familiar with the subject matter, identical 
takes of the same scene often vary several decibels in intensity. 

Volume limiter amplifiers of various types have been in use for some 
time with effective results. They have taken two general forms, and 




FIG. 5. Limiter and amplifier channel. 



are termed compressors or limiter s. Compressors differ from limiters 
only in adjustment. Either may be converted to the other by chang- 
ing the threshold bias on the rectifier supplying the control voltage. 
Compressors, which have had extensive application in the variable- 
area field, 3 compress a range of 20 to 30 db into 10 db. In this man- 
ner changes in input level of 1 db express themselves as changes in 
output beginning with 1 db and gradually diminishing to considerably 
less than 1 db in the range over which it is intended to operate. 

Ideally it would appear that the best device would be one that 
would instantaneously reduce the gain of a system only when the peak 
power exceeded the 100 per cent modulation value, and then slowly 
restore it to normal after the peak has diminished. This device will 
not operate at any value below the 100 per cent point, and for this 






148 



J. K. HlLLIARD 



[J. S. M. P. E 



reason the "set" background noise will not be raised for levels below 
full modulation. 

Since the compressor has no absolute limiting value, as does a 
limiter amplifier, it still is possible to overload the modulator with 
high instantaneous peaks to a greater degree than the limiter. 

Where the signal-to-noise ratio is important, the slope of the input 
vs. output curve beyond the point where limiting or compression takes 
place is important. Fig. 6 shows the input vs. output curve for a 
linear system (A), a 2:1 compression ratio (B), and a 10:1 ratio (C) 
With the lead characteristic of curve C it is possible to increase the 























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-36 30 34 32 30 20 26 24 22 20 IB 16 14 12 10 8 - 



INPUT LEVEL 



FIG. 6. Input-output curve of compressor: (A) for a 
linear system; (B} for a 2:1 compression ratio; (C) for a 
10:1 compression ratio. 



average modulation without danger of overmodulation as compared 
with curve B. This sharper limiting action provides better protection 
against absolute overload than the lower compression ratio curves. 
Fig. 7 is diagram of the limiter amplifier. The first stage contains 
variable-mu tubes of the 6L7 or 1612 types; the second is a conven- 
tional pentode resistance-coupled stage; and the third, or power 
stage, is beam-powered, using 6V6GT tubes. 

There are several reasons for the selection of the 6V6GT as an out- 
put tube in preference to other tubes such as the 6L6, 6F6, 1622 or 
equivalent tubes. Exhaustive tests of this series of tubes have proved 
that the 6 V6GT has several superior features not found in other tubes, 
and yet it has approximately the same maximum power for Class A 
operation. Where some amplification is desirable after the power 






Mar., 1943] 



FILM-RECORDING SYSTEM 



149 



stage, the 6V6GT is 10 to 20 db quieter than any of the other tubes in 
terms of tube hiss, cathode sputtering, and general microphonics. 

It has been observed also that the uniformity among tubes as to 
plate-current balance is exceptionally good. This tube will settle 
down in approximately 1 to 2 minutes after the power is applied, 
whereas other tubes of the group will require approximately 10 to 15 
minutes to become stable, from the standpoint of hiss and general 
quietness of the mechanical parts that produce random pops. The 




FIG. 7. Diagram of limiter amplifier. 

inufacturer of these tubes has recently indicated that forty im- 

)rtant changes have been made in their design that tend to produce 
this outstanding quality. The gain of the amplifier is approximately 
64 db, and the intermodulation is shown in Fig. 8. 

The rectified control-voltage is supplied by a 6H6G tube. It has 
been found necessary to use the glass equivalent where the rectifier is 
intended to operate at an impedance greater than one megohm. The 
metal equivalent has sufficient leakage above one megohm to change 
the threshold bias normally used. 

A balancing potentiometer has been provided in the cathodes of 
the variable-gain stage so that the tube characteristics may be accu- 



150 



J. K. HlLLIARD 



fj. S. M. P. E. 



rately balanced in a dynamic state. Between the variable-gain stage 
and the second stage of amplification inductances are provided from 
each grid to ground, mutually coupled to each other. Thump fre- 
quencies, introduced by the action of the rectifier circuit in changing 
the gain of the system, are then cancelled by the mutual action of 
the coil. This is possible because the thump frequencies are longitu- 
dinal and so appear with the same polarity on each grid. This coil, 
for best cancellation, should be well balanced, with low effective 
winding resistances. For the transmission of the wanted signal, the 



OUTPUT LEVtL OB 



FIG. 8. Intermodulation curve of limiter amplifier. 



inductance coil is a series-aiding shunt from grid to grid, and gives no 
appreciable bridging loss. The thump component is also reduced by 
using a high threshold voltage on the rectifier. 

Fig. 9 04) shows the time required for limiting to take place when 
the amplifier is subjected to a 5000-cycle tone 10 db beyond the 
limiting point as indicated by the meter. It will be observed that 
the first cycle has an overshoot of approximately 3 db, and at the end 
of the third cycle the amplitude is approximately 90 per cent of the 
final value. Each cycle is relatively free from any objectionable 
transient, which indicates its ability to transmit a square- wave signal. 

Since the time of operation is extremely short it was necessary to 
select a frequency as high as 5000 cycles so that the operating con- 
dition could be accurately estimated. This condition was measured 



dar., 1943] 



FILM-RECORDING SYSTEM 



151 



with a 40-volt threshold bias, which corresponds to a 10:1 com- 
pression ratio. 

Fig. 9(C) corresponds to a 2:1 compression ratio, which is approxi- 
mately a 5-volt threshold bias, and more overshoot is observed with 
a superimposed low-frequency component than that of the higher 
threshold bias. Fig. 9(B) is a measure of the release time of the 
amplifier by supplying 500 cycles 10 db into compression and then 
instantly changing the gain to zero compression. Each vertical 




FIG. 9. Oscillograms showing release times for limiting. 

hite line indicates a 0.1 -second interval and it is estimated that the 
point of 90 per cent of final amplitude is reached at approximately 0.7 
second. Fig. 9(D) shows the release time for a 2:1 compression 
ratio, which indicates a higher superimposed low-frequency thump. 

Since the degree of balance in the push-pull stages determines the 
cancellation of the rectifier components, measurements are made at 
frequent intervals. The simulation of the transients occurring in the 
signal is produced by a test unit. 

For the test a 7000-cycle oscillator is keyed at a 2-cycle rate by an 
electronic switch (Fig. 10). The output of this interrupted 7000-cycle 
generator is transmitted through a 5000-cycle high-pass filter which 



152 



J. K. HlLLIARD 



[J. S. M. P. E. 



removes all frequencies below the filter cut-off. The limiter amplifier 
under test is then provided with sufficient 7000-cycle power to operate 
the limiter into 5 db of limiting. The output of this amplifier is then 




FIG. 10. Limiter amplifier balance test unit. 




FIG. 1 1 . Tube balance test unit. 



passed through a 200-cycle low-pass filter to remove the 7000 cycles. 
The remaining signal is then amplified and measured on a volume 
indicator (Fig. 11). With a properly adjusted limiter, these com- 



Mar., 1943] 



FILM-RECORDING SYSTEM 



153 



ponents, set up by the 7000-cycle transient, are a measure of the un- 
balance. An average value of 55 db below the limiting point is main- 
tained for operation up to 5 to 10 db of limiting. 

The use of the pre-equalized channels for film and disk recording 
using the NAB-RMA orthoacoustic standard (Fig. 12) involves certain 
changes to avoid overloads at the higher frequencies when their 
amplitudes become excessive. 

If the pre-equalizer, which raises the high frequencies, is placed 
ahead of the limiting amplifier, the signal-to-thump ratio is less than 
can be achieved by placing the pre-equalizer after the limiting ampli- 




PRE- EQUAL! E 



FIG. 12. NAB-RMA standard equalizers. 

fier. The thump energy, being composed principally of very low 
frequencies, is introduced into the main circuit at a point where the 
maximum low-frequency amplitudes are being transmitted, and for 
this reason the ratio of signal-to-thump is as high as possible. 

With the equalizer after the limiting amplifier, additional carrying 
capacity is needed to overcome the insertion loss of this equalizer at 
low frequencies, and the ability to limit all frequencies to conform 
with the 100 per cent modulation point is lost. In order to provide 
sufficient margin from signal to thump, so that the 50-db range can 
be maintained without critical balancing, this equalizer has been 
placed between the variable-mu stage and the second stage (Fig. 7) . 

An equalizer is provided also in the rectifier circuit to compensate 
for the characteristic of the recording modulator so that the rectifier 
current would have the same characteristic as the modulator for all 
recorded frequencies. In this manner peaks in light- valves, galva- 



154 J. K. MILLIARD U. s. M. p. E. 

nometers, and recorders may be compensated for, so that under no 
condition will it be possible to overload the modulator. 

The design of a peak-limiter amplifier is complicated by the fact 
that three fundamental characteristics of the amplifier are interrelated 
in such a way that a change of one modifies the others. These char- 
acteristics are: 

(1) The operate time, or time required to reduce the gain. 

(2) The release time, or time required to restore the gain to normal. 

(3) The shape of the input vs. output curve after compression begins. 

Thump is rendered negligible by making the loss in the audible 
frequency band of the rectifier circuit as high as possible. This is 
accomplished by arranging the condenser charge and discharge cir- 
cuits of the rectifier so as to assume the proportions of a low-pass 
filter. As a result, the loss through the circuit varies with the product 
of the operate and release times. 

Stability of the unit is provided by the input balancing potenti- 
ometer, the shunt inductance interstage, and the electrical balance of 
the input and output transformers. Thirty-db feedback is provided 
in the last two stages, which reduces the gain to the minimum, so 
that the signal-to-thump ratio at the input will be as great as possible. 

The action of the limiting amplifier is peak-controlled. This means 
that the gain change is proportional to the peak voltage from the 
rectifier in the same manner as in a peak-operated volume indicator, 
whereas the ordinary volume indicator is average-operated. The peak 
factor, or the ratio of peak-to-average value, in a sound signal may be 
as high as 8 to 10 db. For this reason this unit will show limiting 
action 8 to 10 db before non-peak indicators, even though they are 
set up to read alike on a sine-wave calibrating voltage. In general, 
peak operation in d-c control circuits is achieved by allowing the 
rectifier to charge a condenser from a low-impedance source such 
that the grid peak and grid condenser combination has a large R/X 
ratio. 

Since the limiting amplifier is used to record on both film and disk, 
a relay is provided to change the threshold bias from 40 to 80 volts so 
that a 6-db higher limiting point may be obtained, as the disks require 
this additional output. This relay is controlled by a foot-switch so 
that the mixer can change the threshold also for sound-effects, at 
which time considerable Class B signals on the film can be tolerated 
to an advantage. 



Mar., 1943] FiLM-RECORDING SYSTEM 155 

The use of the limiting amplifier over the past nine months in 
large-scale production has shown the benefits to be gained. The mixer 
operator can now concentrate his efforts upon other important phases 
of his work, such as balance and acoustical conditions, without the 
constant worry of overmodulation. As a result, mixing to anticipate 
changes that may or may not come is avoided and the maximum signal 
is always recorded. 

Material having a high peak factor, or transient, such as applause, 
gun shots, noises of kitchen utensils, and general sound-effects, shows 
a very distinct improvement with this device. The modulator is not 
subjected to peaks 10 to 20 db beyond its rated capacity, and as a 
result damage to it is now negligible. 

Peaks up to 5 db can be limited without being apparent to the ear, 
which makes possible the full use of pre- and post-equalization without 
the high-frequency overload that might otherwise occur from time to 
time. One has only to compare recordings made with and without 
the limiter amplifier to realize instantly the benefits obtained, and now 
the long-dreamed-of day has arrived when it is not necessary to 
"ride gain" constantly and to have "mixer's itch" to perform the 
duties of turning in well recorded material. 

PRE- AND POST-EQUALIZATION 

Of the several factors influencing the type of recording character- 



istic giving the best overall results one of the most important is noise 
reduction. In the past, for sound recording on film, a bias type of 
noise reduction has been used. This system consists essentially of a 
device that masks off or limits the unused light not necessary for com- 
plete modulation. The equipment is operated on rectified and 
filtered direct current, which varies in a manner similar to the volume 
variations of the sound. Since the filter has a time-constant, a signal 
of suddenly increasing intensity may overload the modulator and 
produce a clipping effect known as a noise-reduction thump. Also 
the release-time of this equipment is sufficiently long, after the signal 
has been removed, to allow variation in film noise, usually called 
"breathing." Due to these difficulties the signal-to-noise ratio can 
not be materially extended by this method without creating severe 
distortion. 

Noise reduction by the pre-equalization method accomplishes 
beneficial results for two basic reasons: first, the peak energy of 
recorded signals lies in the lower part of the audible spectrum, and, 



156 



J. K. HlLLIARD 



[J. S. M. P. E. 



second, the most objectionable noise from film occurs in the upper 
portion of this frequency spectrum. 

Up to the present time many different degrees and types of pre- 
equalization characteristic have existed in recording circuits. Peaks 
in the response of microphones have provided a variable amount 
of pre-equalization. 

This was unsatisfactory, as the peaks in microphones of the same 
type varied from unit to unit. Light-valve and galvanometer reso- 
nances also have been employed as another type of pre-equalization. 



AVERAGE VOICE CHARACTERISTICS - MEN t VK>MN 



SPEECH INTENSITY IN DB ABOVE 10"' WATT S/tu' 

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FREQUENCY IN CYCLES PER SECOND 



FIG. 13. Average voice characteristics. 

By the reduction of peaks in microphones and modulators so that 
greater stability is achieved, it is now practicable -to apply a larger 
amount of pre-equalization without detrimental effect. 

The reason for introducing pre- and post-equalization into the 
recording and reproducing system is to create a better load-factor 
than would be obtained with the normal characteristic of the system. 

From measurements reported by Sivian, Dunn, and White, infor- 
mation has been made available on the maximum intensity levels pro- 
duced by both large and small orchestras. The average voice char- 
acteristics of both men and women have been determined by Loye 
and Morgan, 4 from which an average peak level intensity can be de- 
rived. This curve shows that peak energy occurs in the neighborhood 
of 500 to 700 cycles, whereas in the case of music the peak intensity 
takes place at a somewhat lower frequency (Fig. 13). Since dialog 
represents the highest percentage of material in a motion picture we 






Mar., 1943] FiLM-RECORDING SYSTEM 157 

must therefore determine the amount of pre-equalization that can be 
utilized to maintain this average load-factor throughout the spectrum. 

The reduction in noise is accomplished by recording the high fre- 
quencies at a much greater amplitude than normal, relative to the 
low frequencies, and in reproduction they are brought back to normal 
amplitudes by means of the reciprocal or post-equalizer. However, 
for a very small percentage of the time the amplitudes of the high 
frequencies may be such that the capacity of the system temporarily 
is not sufficient, and during this time the penalty that must be paid 
is a temporary reduction in gain of the system. 

Normally in orchestral sounds no penalty is observed. However, 
in dialog and sound effects there are detriments in a few cases. In 
general, high-frequency peaks do not produce as noticeable overload 
distortion as do the low-frequency peaks because of their shorter 
duration and because usually their harmonic terms fall outside the 
audible band. However, the overloading may now be eliminated by 
the use of a limiting amplifier. 

Fletcher has used a similar form of pre-equalization for securing 10 
db of noise-reduction on the variable-area stereophonic sound-on-film 
demonstration equipment. 5 Hathaway has reported results both in 
the standard broadcast band and in television sound channels. His 
work is in agreement with others in that with this type of pre-equali- 
zation noise reduction as great as 10 db is obtained at the lower levels 
and somewhat less at higher levels due to the masking effect. 

For several years vertical transcriptions have utilized the pre- 
equalization of the higher frequencies to very marked advantage; 
and during the past two years lateral SSYs-rpm electrical tran- 
scriptions have used the method, and the reduction of disk noise is 
equally effective. 

For the past five years pre-equalization has been used on original 
variable-density recording with a material reduction in noise. It has 
been particularly successful in reducing the "breathing" effect of the 
bias method of noise-reduction. Frequency modulation standards 
now include pre-equalization as part of their program for increasing 
the signal-to-noise ratio. Tube hiss and impulse types of noise are 
apparently reduced to the same extent as are the noises from disk and 
film surfaces. 

Objections have been raised to the use of pre-equalization on the 
basis that the high-frequency overloading would cause increased 
intermodulation and harmonic distortion. However, it has been 



158 



J. K. HlLLIARD 



|J. S. M. P. E. 



observed throughout the past few years, in those systems that have 
utilized pre- and post-equalization that the reverse is true. Both 
dynamic and static tests indicate that the introduction of this system 
reduces the overall distortion very materially. The cleaner re- 
production results also from the decreased intermodulation of the 
signal and the noise. 

CYLINDRICAL LENS 

In a paper presented by Dupy and Hilliard 6 on the use of the 
cylindrical lens, the reduction in intermodulation possible by this 
method, because of the 10-to-l image height reduction, was pointed 



fetHCURY LAMP 




OBJECTIVE LENS 
ME AS CONDENSER EXCEPT 
STOPPED DOWN TO O.5" 



RECORDING DRUM 






FIG. 14. Monochromatic optical system for variable density recording. 

out (Fig. 14). All the present recording machines in this studio, both 
for original and release recording, have been equipped with this device. 
The modulator is now capable of operating over a ==2.5-mil ampli- 
tude without noticeably increasing the intermodulation products due 
to a change in slit width. 

The standard procedure employed in the operation of the modu- 
lator is as follows : The normal spacing of the ribbons is set at 1 mil. 
Sufficient bias current is then applied to reduce the ribbon spacing to 
0.3 mil, which is the equivalent of 10 db of noise reduction. Reverse 
bias also is applied to the ribbons so that it is possible to open them by 
means of noise-reduction current to 2.5 mils. This gives the equiva- 
lent of approximately 17 db of noise reduction. Due to the difficulty 



Mar., 1943] 



FILM-RECORDING SYSTEM 



159 



of maintaining accurate ribbon spacing below 0.3 mil this has been 
chosen as the narrowest operating condition consistent with uni- 
formity of operation. 

The rectangular opening in the pole-face of the light-valve is 
approximately 6 mils wide for which reason amplitudes in excess of 
2.5 mils would cause distortion of the wave-form. Ribbons are 
normally spaced 1 mil so as to reduce the catenary effect during aver- 
age modulation. This is also the best average heating condition for 
the valve, since an amplitude of 2.5 mils requires approximately 
500 milliamperes of current for the sensitivity and tuning frequency 
employed. By this means the change of tuning with modulation due 
to the heating of the ribbons is not more than 200 cycles, using 
10,000-cycle tuning. 




-FILM TENSION 




CONTACT PONT 



FIG. 15. Dual pitch diameter sprocket; for feed action film rides on sprocket- 
tooth step. 

The large 4 3 / 4 -inch diameter sprocket used on a standard variable- 
density recording machine formerly was provided with a relief be- 
tween the film and the base of the drum. Now with the cylindrical 
lens set-up it has been found necessary to maintain a running focus 
condition such that a deviation no larger than 0.2 mil inch is en- 
countered. To permit this small tolerance it was necessary to support 
the film under the track by a solid backing. 

For proper film-running condition the "feed" and "hold-back" 
sprocket for optimum "chain" effect requires different pitch diameters. 
In some cases the same sprocket has been used for both hold-back 






160 



J. K. MILLIARD 



U. S. M. P. E. 



and feed. Under such a condition a dual pitch diameter becomes 
necessary for best performance. The means of achieving this are 
shown in Fig. 15. 

For feed action the larger pitch diameter is required. Therefore, 
the film rides on the step having the larger pitch diameter. In the 
case of hold-back the pitch diameter should be less than the feed 
pitch; hence the film rides on the smaller root diameter of the teeth. 
It was found in practice that a difference in root diameter of 0.4 per 





FLA3 




FIG. 16. Cylindrical lens and matting device. 

cent was sufficient to accomplish the correct "chain" action. The 
use of split film has accentuated the need for correct "chain" action 
diameter due to the fact that only one row of sprockets is performing 
the work. 

Information on the use of the dual sprocket for this use has not 
been found in the literature, and we believe the work of Carlos Rivas 
in this connection is original. 

Fig. 16 is a schematic drawing of the mat used for squeeze-track 
release film. The small cylindrical lens is mounted in the mat as- 
sembly which is held in place by means of a hardened limiting stop. 



Mar., 1943] FiLM-RECORDING SYSTEM 161 

Instead of using a conventional spring to hold the limiting pins in 
contact, a permanent magnet has been used, which facilitates the 
removing of the assembly for maintenance purposes. The flat face of 
the cylindrical lens is 23 mils from the emulsion face of the film. The 
squeeze-track mat is located between the lens and the film. By this 
construction it is possible to locate the mat 6 mils from the surface 
of the film. A distance of at least 6 mils is required to allow a running 
splice to pass. Close proximity of the mat and the film is necessary 
to obtain a sharp outline of the mat on the film so as to reduce the 
edge effect. 

NOISE REDUCTION 

The noise-reduction unit is similar to the one described by Scoville 
and Bell. 7 The operate time is 20 milliseconds and the release time 
70 milliseconds. No threshold adjustment is provided in the noise- 
reduction system since ' 'hush-hush" troubles do not occur with fine- 
grain film and pre- and post-equalization. A margin of approximately 
2 to 3 db is used, which value has been selected on the basis of inter- 
modulation tests. 

In the past a serious limitation has been imposed upon the reverse 
current that could be used in operating the noise-reduction unit due 
to the change in slit width and in the H&D film 
characteristic. However, the wider latitude of 
the present fine-grain negative recording stock 
enables the full dynamic utilization of bias cur- 
rents between 0.3 mil and 2.5 mils without seri- 
ous departure from the straight-line portion of 
the H&D curve, as indicated by intermodula- 
tion and microdensitometer analysis. Over this 
range the compression is not greater than 1 db. 

DAMPING NETWORK 

A damping network consisting of a high-Q res- 
onant circuit is placed across each pair of rib- vah^e damping let- 
bons to utilize the mechanical resonance of the work, 
light-valves. This network (Fig. 17) has suffi- 
cient attenuation at the tuning frequency to provide approximately 
the equivalent of a 30-db shunt at 10,000 cycles, which permits the 
full frequency response of the light-valve up to and through the 
resonance point without generating undesirable transient products 




162 J. K. MILLIARD |J. S. M. P. E. 

(Fig. 18). The transient was made by turning the bias current 
off and on. 

The limiter amplifier protects the ribbons against peaks at high 
frequencies, and since it has been used there has been no breakage of 
light-valve ribbons. This limiting of the peak current also prevents 
the ribbons from being displaced or stretched so as to change the 
static spacing, and as a result greater uniformity of density is main- 
tained. 



FIG. 18. (A) Network across ribbons; (B) no network across ribbons. 
714-C RECEIVER UNITS 

Up to the present time several types of headsets have been used. 
Among them has been the magnetic type of telephone receiver with 
the fixed coil and flat diaphragm. This unit had a very poor tran- 
sient reproduction on square wave-form and had a serious falling off 
in high-frequency response above 3000 cycles, being down at least 20 
db at 5000 cycles. 

Another unit has been the crystal type of headset, with very high 
impedance at all but the low frequencies. Since this unit is the 
equivalent of a condenser, its reactance varies directly with frequency. 
It has poor low-frequency response, and a peak on the high end. 
These units have not been uniform in characteristics, and have a 
tendency to rattle at comparatively high levels. As a result they have 
not had wide application for other than test work. 

A third type of unit that has met with the greatest approval and 
general use for high-quality monitoring has been the dynamic, or 
moving-coil headset. It has better square-wave, or transient, opera- 
tion than other units. Its high-frequency response does not meet 
high-quality standards and its reproduction below 200 cycles is not 
adequate. 



Mar., 1943] 



FiLM-RECORDING SYSTEM 



163 



Another bad feature of all these headsets has been the inability to 
wear the units so as to provide efficient coupling to the ear at low 
frequencies. 

Recently a receiver designed for hard of hearing sets has become 
available that has a sensitivity equal to that of the dynamic headset 
(Fig. 19). The frequency response is reasonably linear from 100 
cycles to 5000 cycles, and there is good uniformity among units. 
The impedance and frequency characteristics are shown in Fig. 20. 
Since the units are fitted into the ear, the loading at low frequencies 
is greatly improved and the leakage of outside noise is reduced con- 






FIG. 19. Headset. 

siderably. For routine operation they help the mixer to achieve a 
better balance, and at the same time they have sufficiently good fre- 
quency response that undesirable extremely low -frequency and high- 
frequency noises are more easily detected (Fig. 21). They provide a 
much closer approximation to the two-way loud speaker and monitor 
and it is expected that they will find wide application. 

To prevent damaging the ear as a result of switching transients for 
abnormally high level, a small varistor may be bridged across the 
headset (Fig. 22). This device has infinite impedance up to a certain 
voltage and then operates as a limiter by changing its impedance to 



164 



J. K. HlLLIARD 



[J. S. M. P. E. 



a relatively low value, and in this manner prevents the diaphragm 
from making abnormally high excursions. The ear-pieces are made 
of lucite, and the receiver is snapped into the ear-piece by the equiva- 



\ 



FIG. 20. 714- C receiver characteristics (measured on 
2 CC coupler). 





























































































LOW FREQUENCY RESPONSE 
714 C VS 705 A RECEIVER 














=8 










DERIVED BY AUDIOMETRIC TEST 














u 

V) 










714 C USES MOULDED EAR COUPLER 
705 A USES SOFT RUBBER EAR CAP 














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FREQUENCY IN CYCLES PER SECOND ..' . '._.', 

FIG. 21. Frequency response of receiver. 

lent of a miniature glove-snap. The new units are now replacing the 
705 units, and our entire mixer staff has been fitted with ear-pieces. 
Straight tips are available for test purposes and are held in place to 
provide the same coupling as those provided in the fitted pieces. 



Mar., 1943] 



FILM-RECORDING SYSTEM 



165 



SIGNAL-TO-NOISE RATIO 

The measured volume range of a symphony orchestra is 78 db, 
according to Fletcher. 8 The use of 200-mil fine-grain film permits a 
signal-to-noise ratio of 50 db. Approximately 16 db of noise reduc- 
tion is used, which brings the usable range up to 66 db. In addition, 
16 db of pre- and post-equalization are used, which gives an effective 
reduction of noise of approximately 8 db more, so that the total 
effective signal-to-noise ratio is 74 db. 



10 



10 
20 

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VARISTOR 








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WITHOUT 
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VARISTOR 




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-20 -10 10 20 



INPUT TO RECEIVERS db/.006 W 

FIG. 22. Effect of bridging varistor. 

By using the fine-grain film, pre- and post-equalization, and 16 db 
of biased noise reduction, we are now able theoretically to come within 
4 db of the complete range of a symphony orchestra with conven- 
tional recording and reproducing circuits. Moreover, on the basis of 
intermodulation measurements, the transient conditions of the system 
are sufficiently good to record applause, piano, choral work, and 
difficult sound-effects, such as tap dancing and the noises of metallic 
objects, without audible rectification or "hush-hush" effects. The 
limiter amplifier contributes greatly to the elimination of peaks that 
would cause overloading and consequent rectification. 

SENSITOMETRY 

Early in 1939 work was undertaken to provide a complete fine- 
grain program for variable-density sound-recording. Since that time 
efforts have been made to produce a very fine-grained negative stock 



166 



J. K. MILLIARD 



fj. S. M. P. E. 



that would have approximately the same sensitometric character- 
istics as the previous stocks without a sacrifice of speed. 

Approximately twelve types of stock have been used in arriving 
at the 230 type of emulsion currently in use. The latter has approxi- 



Z M L 51 ACE 



RELATIVE LOG EXPOSURE 



FIG. 23. H&D curve. Dupont fine-grain film 230-16; negative gamma 0.40. 



mately half the speed of ordinary 
stock and yet retains the fine- 
grain capabilities of other fine- 
grain duplication stocks which 
are extremely slow in speed. 
Fig. 23 shows the H&D curve for 
this stock. 

The operating density of the 
no-signal, 1-mil spaced valve is 
approximately 0.55, and the den- 
sity of the 10-db noise-reduction, 
no-signal track is approximately 
0.38. The range of density ex- 
tends from 0.18 to 0.82 for 90 per 
cent modulation with 16 db of 
noise reduction, and no depar- 
ture from the straight-line por- 
tion of this negative is encoun- 
tered in securing this modulation. 
The unbiased unmodulated den- 
sity is obtained with an incan- 

















































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NEGATIVE DENSITY 



FIG. 24. Print- through curve: 
280-16 negative, gamma = 0.4, 
on Dupont 225-107 positive; over- 
all gamma = 1.62. 



Mar., 1943] FiLM-RECORDING SYSTEM 167 

descent lamp operating at 8.8 amperes in conjunction with the 
cylindrical lens set-up. A print from this negative is made on 225 or 
1302 stock, and the printed- through strip is shown in Fig. 24. The 
prints are made with a 2-mil Corning 587 filter so that the exposure 
is limited to the near ultraviolet region. 



MERCURY ARC LIGHTS FOR RECORDING AND PRINTING 



L'he improved quality of prints made with ultraviolet light has 
n well established. 9 The use of fine-grain film for release printing 
has required increased exposure to offset its slower speed. Since only 
violet and ultraviolet light is needed, a mercury lamp is many times 
more efficient than a tungsten lamp for providing this exposure. 
Normally the mercury lamp is operated with a ballast resistance such 
that the voltage drop in the lamp is approximately equal to the drop 
in the ballast, so that the lamp is held stable at a given pressure and 
current. In order to obtain a range of exposure by varying the power 
supplied to the lamp, some auxiliary equipment must be used to limit 
the wattage to a predetermined value. 

One method used for several years in the recording machine has 
been to cool the lamp by forced air from a fan driven by a small d-c 
motor 'connected across the arc terminals. 10 The method has been 
used with the 85-watt lamp, which is intended to operate on a mini- 
mum of 350 volts and has provided extremely close regulation of the 
exposure. 

Another method that has been found very practicable for printing 
has been to use a photoelectric-cell-controlled lamp in series with a 
resistance adjusted to absorb the difference of voltage between the 
line and that needed by the lamp. The control circuit is shown in 
Fig. 25, and consists of two L-type vacuum tubes connected across 
the lamp so that the plate-to-cathode current of these tubes is in 
parallel with the lamp. Plate current is adjusted to approximately 
75 milliamperes, which is half way between zero and the maximum 
allowable current. The grid voltages are then varied so as to render 
the tubes capable of changing the current through the lamp over the 
range of to 150 milliamperes. The control grids are operated by the 
amplified voltages from a photoelectric cell which derives its light 
from the optical path between the lamp and the film. A 929 blue- 
sensitive photoelectric cell is connected in series with a small micro- 
ammeter. In this manner the meter serves to indicate exposure, and 



168 



J. K. MILLIARD 



[J. S. M. P. E. 



it is possible to replace lamps from time to time and be able to repeat 
these exposures consistently. 

Since the maximum rating of the cell is 20 microamperes it is neces- 
sary to restrict the metered light to less than this amount. The volt- 
age generated by the photoelectric cell across a resistor Rl (Fig. 25) 
controls the bias on the control grid of amplifier V\. If no current 
flows in the photoelectric cell the bias of V\ becomes zero. This 
allows this tube to draw current through its plate resistor, and the 
plate assumes a low potential with respect to its cathode. The plate 
of this tube is connected through a battery to the control grids Vz and 
V^ in such a way that the grids of these tubes are always this amount 
negative with respect to the plate of V\. Therefore, whenever the 
plate of Vi assumes a potential less than 22 y 2 volts above its cathode, 








A 


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I'lT 


A 


1 


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rf 


(K 


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FIG. 25. Control circuit. 



the grids of Vz and V* become negative with respect to their cathodes 
and the plate current is varied. 

Since these tubes have a high-amplification factor, a very small 
change of photoelectric cell current is capable of completely control- 
ling the plate currents of the last two tubes, which in turn control 
within very close limits the exposure provided by the mercury arc " 
lamp. The circuit is arranged so that an increase of light on the 
photoelectric cell will reduce the current through the lamp and corre- 
spondingly reduce the exposure of the film. Inasmuch as the operation 
of the control circuit is practically instantaneous, any fluctuations in 
the arc lamp or changes in supply voltage that might vary the ex- 
posure are suppressed. This type of control circuit operates very 
satisfactorily with low-voltage mercury arc lamps of 100 and 250- 
watt size and has made possible the use of mercury lights from a 
220-volt d-c supply. 



Mar., 1943] 



FILM- RECORDING SYSTEM 



169 



PORTABLE APPARATUS 



i- 

This studio uses three types of portable apparatus in addition to 
the fixed channels. One type is known as a dolly channel, 11 in which 
the full complement of fixed channel apparatus is mounted on a 
rubber- tired dolly not connected to the main recording plant, so that 
it can be wheeled about on the stages. 

The second consists of the same equipment mounted on a truck so 
that it can be used for exterior location work. 

The third type is known as a super-portable type. It is mounted 
in small cases in such a manner that one man can carry and set up the 







VIID-RAN&E ADDING 



MID-RANGE SU_BTRACTINCi 





LOW RANGE 



HIGH RANGE ADDING 



FIG. 26. Constant- J5 variable equalizers. 



individual units. It is driven by a d-c interlocking motor system 
utilizing a 110- volt bank of motorcycle storage-batteries. 

The essential elements of this system are the microphone and its 
amplifier, a small two-position mixer, the limiter amplifier, noise- 
reduction system, and miscellaneous control apparatus which connects 
to the recording machine. The amplifier and noise-reduction appara- 
tus employ the standard channel limiter and noise reduction system, 
which is mounted in a small rack. The total equipment weighs ap- 



170 



J. K. MILLIARD 



[J.S. M. P. E. 



proximately fifty-five pounds. By using the same type of equipment 
throughout the system it becomes very easy to replace any defective 
unit with a spare. 

RE-RECORDING EQUALIZERS 

The demands placed upon a re-recording channel are numerous 
and severe. Because of the many ever expanding tools to create the 



ATTENUATION DIAL 






3,000 



Q, 00 



CURVE OBTAINED BY VARYING FREQUENCY DIAL 

0DB ATTENUATION. LR MR KEY ON MR. 



FIG. 27. Typical Constant-5 equalizer curves. 



10 100 1000 C.P.S. 

FIG. 28. Typical Constant-./? equalizer curves. 

effects required, circuit and equalization problems become somewhat 
complex in terms of the original recording channel. 

Equalization is used to produce uniformity of quality; provide 
telephone, dictaphone, or radio quality from an otherwise normal 
scene; add synthetic reverberation over various frequency bands; 
and change delivery effort. 






Mar., 1943] FILM-RECORDING SYSTEM 171 



The equalizers now in use for correcting the overall characteristics 
in re-recording are the result of long study and effort to arrive at a 
form that will help to correct the various acoustic and effort condi- 
tions encountered in production. The type now used is known as a 
constant-!? type, since its half-loss point in decibels for any amount 
of equalization is always maintained at the same distance from the 
resonance point (Fig. 26). The equalizer has been set up on the basis 
that this half -loss point will always be one octave distant from the 
resonance point either in the add or subtract setting. 

Originally the equalizers used were designed for the proper shape 
at 8 db of equalization, but when used (as was commonly the practice) 
at 2 to 4 db, the band width of equalization was extremely small and 
did not compensate accurately for losses normally encountered. 
These units are so designed as to provide the necessary addition or 
subtraction of low-frequency bands in ten uniform steps from 50 to 
800 cycles, and ten high-frequency bands from 1000 to 8000 cycles, 
over a range of 8 db. 

These units are built in banks of three, and a selector switch is 
provided so that during rehearsal a combination can be set up so that 
the preset equalization can be inserted rapidly. The characteristics 
of these equalizers are shown in Figs. 27 and 28. As these equalizers 
are operated at comparatively low level, extreme care has been taken 
in the shielding of these units. 

The electrical design of these equalizers is believed to be unique 
and has been developed by Harry Kimball, in our Sound Department. 

RE-RECORDING MIXERS 

It has been found convenient to provide re-recording mixer facili- 
ties in two banks of eight units each. In order to provide sufficient 
flexibility so that equalization can be introduced in individual posi- 
tions or group equalization in banks of two, four, or eight positions, 
mixing coils were used, thus reducing the loss to a minimum. A 
diagram of such a mixer is shown in Fig. 29. 

SYNTHETIC REVERBERATION 

Several methods have been made available for adding synthetic 
reverberation to recording material. Until recently staggered, or 
offset tracks, reverberation chambers, and reverberation pipes have 
been utilized with considerable success. 

Recently a device known as a reverberstat has been made available 



172 



J. K. MILLIARD 



[J. S. M. P. E. 



for this purpose. It consists essentially of a permanent-magnet loud 
speaker actuating a rocker-arm to which springs are attached, which 
set into vibration a piezoelectric crystal. The springs are surrounded 
by tubes of oil which provide the necessary damping. The vibrations 
of the crystal set up an electric current which is then amplified and 




urr MIXK POSITION 



FIG. 29. Dubbing mixer circuit. 



combined with the original signal. The time of reverberation is 
controlled by the length of the springs and the oil damping around 
the springs. This device is made as a compact unit approximately 
four feet long, six inches wide, and three inches deep. It does not 
occupy any appreciable space as compared with the acoustical cham- 
bers required by the other methods and is not suceptible to outside 
noises to the same degree. For this reason it can be mounted con- 
veniently close to the recording apparatus and becomes a very prac- 
tical tool for producing synthetic reverberation. A cross-section of 
this equipment is shown in Fig. 30. As many as three such units are 
used at once to create the necessary reverberation in dialog and music 
tracks, using different equalizers, depending upon the type of rever- 
beration required. 



Mar., 1943] FILM-RECORDING SYSTEM 

CONSTRUCTION DETAILS OF TRANSFORMERS 



173 



The transformers used in the construction of all amplifiers are the 
result of considerable study and development to achieve the necessary 
reduction in intermodulation products, extend the frequency range 
with freedom from resonance, provide accurate balance at high fre- 
quencies, and provide a large amount of magnetic shielding, as Well as 




FIG. 30. Reverberation unit. 

electrostatic shielding between primary and secondary, to avoid 
radio frequency pick-up and static disturbances. 

Numetal is used in the input transformers, which are designed to 
operate at levels lower than 30 db. The characteristic of the metal 
is such that very low induction values are required to keep the eddy- 
current losses from becoming excessive. It is not necessary to load 
the secondary as in the case of a silicon steel core. The flux-density 



174 J. K. HlLLIARD [J. S. M. P. E. 

of these cores runs around 10 to 15 gauss, which is on the toe of the 
induction curve, so that no appreciable change in inductance is 
caused with the varying signal current. Fourteen-mil laminations 
are used to minimize the eddy currents. 

The shielding is provided by the use of round cans made of Alle- 
ghany metal. The amount of shielding is approximately 1 db per mil 
of thickness. A copper can is inserted into the nest to provide a 
short-circuited turn of low resistance and to increase the high-fre- 
quency shielding. The window of the lamination is completely filled 
with copper so as to maintain as low an insertion loss as is possible. 
The composition of the Numetal is roughly 76 per cent nickel, 20 per 





FIG. 31. Exploded view of small input transformer and shields. 

cent iron and a very slight percentage of copper, while the Alleghany 
metal is roughly 47 per cent nickel and 53 per cent iron. An exploded 
view of a small input transformer and shields is shown in Fig. 31. 

INTERMODULATION 

The entire channel specifications for amplifiers, equalizers, modu- 
lators, and film processing are based upon the intermodulation 
method. The use of this method over the past two years has indicated 
its practical value in measuring distortion in a quantitative manner. 
It is less laborious than the harmonic method and yields results that 
are more compatible with ear-listening than previously used methods. 
The total harmonic method is of little value in determining which 
type of distortion is most unpleasant to the ear, and authorities are 
recommending that its use be discontinued in favor of other dynamic 
tests such as square-wave and intermodulation methods. 

The development of sound recording since its inception can be 
visualized as a series of steps. Those first indelible beginnings of 
motion picture sound, which lasted until about 1935, were so crowded 
with recording difficulties that no other problem could be simultane- 
ously attempted. During the next two years or so a large share of 
our energy was directed toward improving theater reproduction. 12 , 



Mar., 1943] FiLM-RECORDING SYSTEM 175 

The last two years have again taken us back to the problem of 
improving recording. The sound-recording engineer has at last had 
an opportunity to give careful attention to some of the finer points of 
the technique. The result has been a higher standard of recording 
made possible by fine-grain films, limiter amplifiers, peak-operated 
noise-reduction units, new types of microphones, lower intermodu- 
lation, and other improvements mentioned before. 

The present national emergency which we are facing has put 
drastic limitations upon all future plans. Further large-scale refine- 
ments in recording technique must undoubtedly be postponed until 
after the successful termination of the present crisis. I wish to thank 
the entire Sound Department staff for their generous help in making 
this paper possible. 

REFERENCES 

1 FRAYNE, J. G., AND SCOVILLE, R. R.: "Analysis and Measurement of Dis- 
tortion in Variable-Density Recording," J. Soc. Mot. Pict. Eng., XXXII (June, 
1939), p. 648. 

HILLIARD, J. K. : "Distortion Tests by the Intermodulation Method," Proc. 
IRE (Dec., 1941), p. 614. 

2 MARSHALL, R. N., AND HARRY, W. R. : "A Cardioid Directional Microphone," 
/. Soc. Mot. Pict. Eng., XXXIII (Sept., 1939), p. 254. 

3 AALBERG, J. A., AND STEWART J. G.: "Application of Non-Linear Volume 
Characteristics to Dialog Recording," /. Soc. Mot. Pict. Eng., XXXI (Sept., 
1938), p. 248. 

4 LOYE, D. P., AND MORGAN, K. F.: "Sound Picture Recording and Repro- 
ducing Characteristics," /. Soc. Mot. Pict. Eng., XXXII (June, 1939), p. 631. 

5 FLETCHER, H. : "The Stereophonic Sound-Film System General Theory," 
/. Soc. Mot. Pict. Eng., XXXVII (Oct., 1941), p. 331. 

6 DUPY, O. L., AND HILLIARD, J. K. : "A Monochromatic Variable- Density Re- 
cording System," /. Soc. Mot. Pict. Eng., XXXVI (Apr., 1941), p. 366. 

7 SCOVILLE, R. R., AND BELL, W. L. : "Design and Use of Noise-Reduction Bias 
Systems," J. Soc. Mot. Pict. Eng., XXXVIII (Feb., 1942), p. 125. 

8 Cf. ref. 5. 

9 FRAYNE, J. G., AND PAGHARULO, V.: "The Effects of Ultraviolet Light on 
Variable- Density Recording and Printing," J. Soc. Mot. Pict. Eng., XXXIV (June, 
1940), p. 614. 

10 DUPY, O. L., AND HILLIARD, J. K. : "Obtaining Increased Illumination for 
Fine-Grain Film Recording," Amer. Cinematographer , XXI (Jan., 1940), p. 36. 

11 PRATT, C. S.: "MGM Portable Dolly Channel," J. Soc. Mot. Pict. Eng., 
XXXIII (Nov., 1939), p. 578. 

12 HILLIARD, J. K. : "A Study of Theater Loud Speakers and the Resultant De- 
velopment of the Shearer Two-Way Horn System," /. Soc. Mot. Pict. Eng., XXVII 
(July, 1936), p. 45. 



MAINTAINING PROJECTION STANDARDS IN WAR TIME* 
LESTER B. ISAAC** 

Summary. A discussion of the importance and methods of maintaining high 
standards of projection during war time, with particular reference to the procedures 
followed in Loew's theaters to enlist the assistance of the theater personnel. 

We must not minimize the importance of our immediate re- 
sponsibilities and occupation. It has been conclusively proved in 
England and in this country that motion pictures are highly essential 
for the maintenance of public morale and the entertainment of the 
armed forces. It is therefore a duty, a patriotic service, to make sure 
that our job is well done. There must be no undue or unnecessary 
lowering of the projection standards it has taken 40 years to es- 
tablish. 

What is meant by good projection and what are the reasons for its 
importance? It is now generally accepted that the image on the 
screen and the audible sounds that emanate therefrom are the essentials 
of motion picture entertainment. Of course, comfortable seats and 
other conveniences, carpeted floors and embellishments are desirable, 
but the fact remains that it is the picture on the screen that fills the 
seats and holds the attention of motion picture patrons. Motion 
pictures are a great source of recreation for our men in the military 
service and their enjoyment is not less keen because in some instances 
they sit on hard -bottom chairs which may rest on dirt flooring. 

Our subject is maintenance of projection standards in war time. 
No attempt will be made to submit a mere instruction sheet, for we 
must assume this paper is intended for experienced projectionists, 
skilled technicians, managers, and owners familiar with practical 
theater operation. Technical books and trade publications will 
continue to supply any further information that may be required. 

The report of the Projection Practice Sub -Commit tee of the 
Society of Motion Picture Engineers' Theater Engineering Com- 

* Presented at the meeting of the Atlantic Coast section, September, 1942. 
** Loew's, Inc., New York, N. Y. 
176 



WAR TIME PROJECTION STANDARDS 177 

mittee, in collaboration with the IATSE and MPMO giving in de- 
tail the 10-point program cooperating with the Government National 
Conservation Program had a far-reaching effect. It was a splendid 
job and well deserved the attention it attracted. 

It is true, of course, that like any other paper it is open to additions, 
corrections, and suggestions. Continued interest in the subject is 
part of the value of such papers. If what is presented in this paper 
receives a small part of the attention given to conservation we can 
feel assured that projection standards will not be neglected. There 
is danger, however, that projectionists, theater owners, managers, 
and others may feel that conservation is an excuse for lowered 
standards and mistaken economics. Even the present serious con- 
dition is not a justification for unnecessary economies that may 
affect the physical well-being of patrons as well as reduce their en- 
joyment of the picture. 

Any change that may lead to a permanent acceptance of poor 
projection would be to nullify 40 years of effort by technicians to 
present motion pictures that retain all that the producer, director, 
and artist have put into them. Every reproduction should retain 
as far as possible the full photographic detail and charm of the 
artistic effort that went into the original performance, production, 
and recording. These are the things all technicians have fought 
for hard and valiantly. They are the things to which the Society 
of Motion Picture Engineers, the Academy of Motion Picture Arts 
& Sciences, the American Projection Society, and the Projection 
Advisory Council sought to establish through collective activities. 
The quality of projection, sound and visual, should not be destroyed 
or even reduced temporarily, except for most urgent reasons and 
until all other measures have been tried and failed. 

Peacetime procedure is not sufficient under present conditions, and 
e hope that theater owners and managers will take increased interest 
projection and projectionists. Much can be accomplished by 
collective effort and cooperation. This is not the time for criticism 
of either personnel or equipment. If the equipment is out of order, 
the owner will be out of luck, and the projectionist out of a job if it is 
found necessary to close down the house. It is no longer possible 
to expect prompt service from supply houses. They have done a 
remarkably good job in the past, but that is over for the present. 
Manufacturers will be unable to supply new equipment or parts. 
American initiative and self-reliance in the pioneer days of motion 



178 L.B.ISAAC [J. S. M. P. E. 

pictures played an outstanding part in building up the motion picture 
industry and will not fail us now. System and organization will, 
of course, supplement the ability and effort of the individual. One 
of the outstanding developments of the past year has been the ap- 
pointment of educational committees by IA Local unions throughout 
the United States and Canada. The purpose of these committees 
is to discuss technical problems of projectionists, to be ready foi 
emergencies, but most of all to prevent the closing down of theaters 
because of defective projection equipment. 

Theater owners and managers will find it greatly to their advantage 
to take an interest in the proceedings of technical organizations in 
this field. Any support given to the educational activities of I A locals 
will prove highly profitable in many ways. Methods must be found 
to secure full cooperation. Theater owners and projectionists now 
more than ever have interests in common. The current meaning of 
"The show must go on" is that equipment should be kept in order 
at all times and no effort spared to keep theaters open if it is in the 
power of projectionists and technical men to prevent their closing. 

Loew's theaters have endeavored always to give projectionists 
full encouragement in their efforts to improve projection. A recent 
activity now in successful operation in the issuance of a limited 
number of certificates of merit presented to Loew's projection-room 
staffs who indicate exceptional interest in their work. These certifi- 
cates of merit are tangible evidence of the efforts Loew's has made 
for many years to raise projection standards. We believe some- 
thing similar to this, at least in spirit, will be found of practical value 
by all theater owners. 

The control system in use by Loew's has been developed during 
the past 16 years. It can be readily adopted by small chains and its 
fundamentals will be found useful by even the most moderate-size 
single theater. It is true it may take a little while to get the system 
in practical operation, but it will prove of invaluable assistance in 
preventing neglect at any time and particularly helpful in avoiding 
serious consequences during the war period. 

CONTROL SYSTEM 

(1) A questionnaire is supplied which gives a complete history 
of the theater from the date of opening; the type and serial numbers 
of all equipment contained in the projection room, together with the 



Mar., 1943] WAR TIME PROJECTION STANDARDS 179 



sizes of all wires, conduits, and fuses, and a complete inventory of all 
supplies and spares. 

(2) A complete record of all supplies as to type, quantity, and 
date received. 

(3) A repair record showing the exact date each piece of equip- 
ment was repaired, and the cost of same. 

(4) Projectionists Film Report: This form is used for keeping 
records of the condition of the film when received at the theater. It 
serves also to indicate the condition of the projectors in case of damage 
to the film during its run in any particular theater, and prevents 
carelessness and unnecessary damage of film. 

(5) Carbon Consumption Form: A weekly report that shows 
also whether or not the illumination system is performing correctly. 
These reports are averaged over a certain number of weeks and if 
the equipment is functioning correctly and the proper current is being 
used, the overall average will indicate correct consumption. 

(6) Monthly Report of Projectionists: This report covers a 
complete inspection of all equipment and the projectionists' opinion 
as to its condition. These reports are carefully checked and any 
indication of defect is immediately corrected. 

(7) Bulletin Form: At required intervals a bulletin is issued to 
all theaters in the circuit containing information relative to eliminat- 
ing troubles with various elements of the equipment or recommend- 
ing additional adjustments that have been found advantageous. 
This form is used also to advise the projectionists in advance of any 
new equipment that his theater is scheduled to receive, or any 
changes in supplies, such as carbons, etc., giving all details as to the 
handling of the new material. 

Through this control system, together with other records that we 
maintain in our office, we have on hand a complete history of each 
and every unit of equipment, covering its complete physical con- 
dition at all times. The control system is the foundation of proper 
maintenance of projection standards in war time as well as under 
normal conditions. 

Prior to 1940 it was our policy to repair projection mechanisms once 
a year and lamps once every two years. The program permitted 
projectionists to secure the best possible screen presentation and at 
the same time kept film damage at a minimum. We adhered to this 
policy for many years and came to the conclusion that after a reason- 
able period of use continued expense for repairs was merely buying 



180 L. B. ISAAC 

old equipment on the installment plan. The cost of unnecessary 
damage to film and the lack of wisdom in continuing to repair old 
equipment are thoughts that should receive the attention of the 
motion picture industry when we return to normal conditions. Like- 
wise, the advantages of a third projector, or an extra mechanism, 
intermittent movement, and spare parts will receive more attention 
in the future than they have in the past. 

Late in 1939 we made a survey of equipment in Loew's theaters, 
and as a result set up a program for the replacement of projector 
mechanisms and arc lamps. Prior to this we had made experiments, 
and when we were satisfied that the equipment we had been testing 
met all our requirements, orders were placed. Now a large 
number of our theaters are in a much better position to maintain 
projection standards for the duration. On some kinds of equipment, 
we are, however, no better off than many other theaters. We must 
continue to practice the same care in order to avoid troubles caused 
by present shortages. Such a situation is particularly disturbing to 
us as we have always taken great pride in the high quality of Loew's 
projection. 

It is possible that others may feel that our standards are too high 
but they have proved very practical and highly profitable. It is a 
great satisfaction to us to know that we have not had a single fire 
due to faulty equipment. Film mutilation is practically nil in our 
theaters and we are definitely proud of the results on our screens. 
It is possible that many will believe that the things we have done are 
due to the size of our organization, great facilities and vast ex- 
penditures, but this is an error. Each Loew's theater must pay 
its way through the revenue received from its own box-office. 

From the time we made up the budget for general replacement 
of mechanisms and arc lamps to actual installation, we were kept 
busy for nearly 30 months. Scheduling shipments and arranging 
for changeovers was no small task. What we did use in liberal 
quantities was good judgment and foresight. There is no monopoly 
of vision, and even under present conditions looking ahead will enable 
many theaters to get by under adverse circumstances. All these 
details are submitted in the hope they will offer suggestions that 
will enable owners to carry on and maintain projection standards 
in the face of every handicap created by war conditions. 



THE FOCUSING VIEW-FINDER PROBLEM IN TELEVISION 

CAMERA* 



G. L. BEERS** 



Summary. The technical excellence of a television program may frequently de- 
pend upon the characteristics of the view-finder used in the television camera. Condi- 
tions peculiar to television make it desirable that television camera view-finders be of 
the focusing type. The requirements of an ideal view-finder of this type are discussed. 
During the past ten years a number of view-finder arrangements have been investigated 
in connection with the development of television cameras. Several of these are de- 
scribed and their relative merits indicated. 



One of the most essential elements in a television camera is the 
view-finder. On its characteristics may depend the technical ex- 
cellence of the television program. The desirability of minimizing 
operating personnel and the necessity for keeping a camera in prac- 
tically continuous operation during television programs of one or two 
hours make it necessary that the view-finder be of the focusing type. 
Such a view-finder not only provides a view of the scene which is 
included in the field of the camera but also indicates when the lens is 
properly focused on the desired scene. 

During the past ten years a number of focusing view-finders were 
investigated to determine their suitability for use in television cam- 
eras. Brief mention of some of these arrangements has already been 
made in the technical literature on television equipment. Practical 
operating experience with several view-finders both in the studio and 
outdoors has established certain requirements which an ideal view- 
finder should meet. It is the purpose of this paper to discuss these 
requirements; to describe briefly several of the view-finder arrange- 
ments which have been investigated and to indicate their relative 
merits. 



* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received Aug. 1. 
1942. 

** RCA Manufacturing Co., Camden, N. J. 

181 



182 



G. L. BEERS 



[J. S. M. P. E. 





No. 1 


No. 2 


No. J 


No. 4 


No. 5 


No. 6 


No. 7 


View-Finders 


Mi rror Arrangement for 
Observing the Optical 
Image on the Mosaic of 
the Pick-Up Tube 


Semi Silvered Mirror 
Arrangement Utilizing 
Camera Lens to Pro- 
duce Image on View- 
ing-Screen 


Kinescope or Elec- 
tronic View-Finder 


Kinescope View-Finder 
with R.emote Focus 
Control 


Split Image View- 
Finder 


Duplicate Lens 
View-finder 


Combination Dupli- 
cate Lens and Kine- 
scope View-Finder 


Ideal View-Finder 
Requirements 


No. 1 
















Provides accurate indi- 


No 


No 


No 


No 


Question- 


Yes 


Yes 


cation of focus under 










able 






all conditions 
















No. 2 
















Accurately defines scene 


No 


Yes 


No 


No 


Yes 


Yes 


Yes 


in television picture 
















and gives view of 
















some additional area 
















No. 3 
















Provides image of satis- 


No 


No 


Yes 


Yes 


Question- 


Yes at 


Yes 


factory size and 










able 


present 




brightness 
















No. 4 
















No special adjustments 


Yes 


No 


Yes 


Yes 


No 


No 


No 


required when pick- 
















up tubes or lenses are 
















interchanged 
















No. 5 
















Does not require a seri- 


Yes 


Yes 


No 


Yes 


Yes 


No 


No 


ous increase in the 
















size and weight of the 
















camera 

















REQUIREMENTS OF AN IDEAL FOCUSING VIEW-FINDER FOR 
TELEVISION CAMERAS 



The requirements of an ideal view-finder may be stated as follows : 

(1} The view-finder should at all times accurately indicate when the camera is 
in focus on the desired scene or object. 

(2) The view-finder should not only define that portion of the scene which is 
being converted into the television image but also should reproduce a sufficient 
portion of the scene outside the camera field so that the cameraman will know in 
advance what the television picture will include if he pans the camera in any direc- 
tion. 



Mar., 1943] FOCUSING VlEW-FlNDER PROBLEM 183 

(5) The view-finder should provide an erect image which is correct left to right 
and of sufficient size and brightness to minimize eye strain. 

(4) The view-finder should not unduly complicate the procedure of interchang- 
ing camera lenses or pick-up tubes. 

(5) For portable pick-up work the view-finder should not contribute sub- 
stantially to the size and weight of the camera. 

It will be noted that the first three of these requirements deal with 
performance whereas the last two are concerned primarily with 
operating convenience. 

In order to appreciate the significance of these requirements it is 
of interest to discuss them in connection with the two general groups 
of view-finders into which the several individual view-finders are 
subsequently classified. For the purpose of this discussion the first 
group will consist of those view-finders which derive the view-finder 
image either directly or indirectly from the camera lens. The second 
group includes those which make use of a separate optical system for 
producing the view-finder image. 

Requirement No. 1. Requirement No. 1 specifies that the view- 
finder should at all times accurately indicate when the camera is 
"in focus" on the desired scene or object. Practical operating ex- 
perience has shown that in respect to this requirement it is desirable 
that the camera man be aware of a degradation in picture detail due 
to improper focus before the loss in resolution is apparent to the 
television audience. The view-finders in group No. 1 have several 
limitations with respect to this requirement. When the scene which 
is being televised is sufficiently illuminated so that the camera lens 
can be stopped down to provide greater depth of focus the view- 
finders in this group do not provide an accurate focus indication 
since the view-finder image has the same depth of focus as the camera 
image. In other words, no apparent change' in detail is observed by 
the cameraman as the lens is moved back and forth through an 
appreciable range. This limitation may not be particularly apparent 
to the television audience from the standpoint of picture detail but is 
likely to be disturbing for another reason. Under this condition the 
cameraman has a tendency to move the camera lens back and forth 
to determine by approximation the center of the range over which 
no effect on picture detail is observed and thus establish the "in focus" 
position of the lens. As the lens is moved back and forth, the area 
included in the television image changes in such a manner that the 
sides of the picture appear to move in and out; an effect which is 
disturbing to most observers. 



184 G. L. BEERS [J. S. M. P. E. 

Another result of this inaccurate focus indication is encountered 
when the camera is used under conditions where the illumination may 
vary suddenly through a fairly wide range. Such conditions are 
frequently encountered in outdoor pick-up of sporting events or spot 
news, etc. If the lens is stopped down and the camera is inaccurately 
focused on a scene in bright sunlight and the sun subsequently goes 
behind a cloud, making it necessary to increase the lens aperture, the 
camera will be out of focus. The focusing readjustment which is 
then required would have been avoided if the view-finder had met 
requirement No. 1. 

The view-finders in group No. 2 can all be made to meet require- 
ment No. 1 provided they are constructed with sufficient mechanical 
rigidity to maintain, at all times, the proper alignment between the 
optical systems for the view-finder and pick-up tube. 

Requirement No. 2. Requirement No. 2 states that the view-finder 
should always provide an image of and accurately define that portion 
of the scene which is being converted into the television picture and 
should also provide a view of at least a small part of the scene on each 
side of the television picture area. Unless the first part of this re- 
quirement is fulfilled the cameraman may not know, for example, 
whether or not an individual's head is in the picture. The second 
half of this requirement gives the cameraman an indication of what 
will be included in the picture if he pans the camera in any direction. 
The need for this information may depend to some extent on whether 
the camera is being used in the studio or outdoors. From one stand- 
point, there is less need for this additional view-finder image area in 
the studio because studio programs are usually rehearsed several 
times. On the other hand, in studios several sets are frequently used 
in a limited space so that a camera can be changed quickly from one 
scene to another. This makes it necessary for the cameraman to 
know what is included in a small area outside the field of his camera 
so that he does not inadvertently include an edge of an undesired set 
in the picture. If the view-finder does not provide an image of this 
additional area it is frequently necessary for the cameraman to move 
his head sufficiently so that he can look along one side of the camera 
to determine the effect of panning the camera in a desired direction. 
Not only is this inconvenient but when the camera man looks around 
the camera at the brighter scene and then again looks at the image in 
the view-finder it is necessary for his eyes to readjust themselves to 
the difference in the light intensity. In outdoor pick-up work such 



Mar., 1943] FOCUSING VlEW-FlNDER PROBLEM 185 

I 

as sporting events, where the action is unpredictable, if the camera- 
man looks around one side of the camera he may lose the action 
altogether before he has time to again look into the view-finder. 

In general, the view-finders in group No. 1 do not meet require- 
ment No. 2 since the view-finder image which they provide is ob- 
tained from the camera lens and covers the same picture area as the 
television image. 

The view-finders in group No. 2 make use of a separate optical 
system and therefore can be made to provide a view of some of the 
scene around the area which is converted into the television image. 
Such view-finders are, of course, provided with hair lines on the 
vie wing-screen or some other expedient which indicates the actual 
area of the scene which is included in the television picture. It is 
essential that the view-finders in this group be provided with some 
means which will correct for parallax between the two optical system. 

Requirement No. 3. The ideal view-finder requirement No. 3 is 
met if the view-finder provides an erect image which is correct left 
to right and of sufficient size and brightness to minimize eye strain. 
A difference of opinion may exist as to the necessity of having the 
view-finder image erect and correct left to right. If the cameraman 
has received considerable training with cameras providing images 
which are inverted and reversed left to right such a view-finder is 
undoubtedly satisfactory. He will then have developed the proper 
coordination between the image he sees in the view-finder and the 
direction in which he must move the camera to produce a desired 
effect. On the other hand, in a new field such as television where it 
will be necessary to start with relatively untrained personnel it is 
felt that the corrected view-finder image will be more satisfactory. 

With respect to the other stipulations in requirement No. 3 a view- 
finder image at least 3X4 inches at a viewing distance of 12 inches 
has been considered to be satisfactory. The image should be as 
bright as possible. No difficulty has yet been encountered from 
having the view-finder image too bright. The ability of a specific 
view-finder arrangement to meet requirement No. 3 is basically de- 
termined by the amount of light which it supplies to produce the 
optical image since if sufficient light is available an optical system 
can be used to increase the image size and reverse it in either or both 
directions. 

The problem of providing sufficient light to produce a satisfactory 
view-finder image is becoming more difficult as the sensitivity of 



186 G. L. BEERS U. S. M. P. E. 

camera pick-up tubes is increased. This limitation may ultimately 
make it necessary to resort to a highly complicated view-finder ar- 
rangement which will be described later. 

Requirement No. 4. This requirement is concerned with the effect 
of the view-finder on the ease of interchanging either pick-up tubes 
or lenses. Since emergencies may arise which make it necessary to 
change pick-up tubes and since it is frequently desirable to change 
to a different focal-length camera lens it is essential that these changes 
be made in the shortest time and with the least inconvenience. 

This requirement is met to the greatest extent by the view-finders 
in group No. 1 since they derive the view-finder image from the 
camera lens. The view-finders in group No. 2 which use a separate 
optical system for producing the view-finder image all contain some 
element which must be adjusted to provide satisfactory optical 
alignment between the two optical systems when pick-up tubes are 
changed. Up to the present time it has been impracticable to manu- 
facture pick-up tubes with sufficiently close tolerance on the position 
of the mosaics and other elements of the tubes to make them optically 
interchangeable. Some adjustment is therefore necessary so that 
the view-finder image and the image on the pick-up tube are "in 
focus" simultaneously. It is possible to shift the position of the 
pick-up tube in a camera to obtain satisfactory optical alignment 
between the two optical systems. The size and weight of the pick-up 
tube with its deflecting yoke, however, make it much more practi- 
cable to move a ground glass screen or some other element in the 
view-finder to provide the necessary alignment between the two 
optical systems. 

No serious complications are encountered in interchanging lenses 
of different focal lengths in cameras employing the view-finders in 
group No. 1 since only the camera lens is changed. 

The additional lens required with the dual lens view-finder arrange- 
ments in group No. 2 makes the problem of interchanging lenses 
somewhat more difficult. This is particularly true where the lenses 
are large and heavy such as those having focal lengths of 20 in or 
more and apertures of the order of //4.5. 

Requirement No. 5. Requirement No. 5 is based on the desir- 
ability of keeping the size and weight of television cameras for port- 
able pick-up work at a minimum. Studio cameras are usually semi- 
permanently mounted on large dollies similar to those used in motion 
picture work and the size and weight of the television camera for 



Mar., 1943] 



FOCUSING VIEW-FINDER PROBLEM 



187 



studio work are therefore not a primary consideration. Portable 
television cameras, however, are used on conventional tripods and 
are set up and subsequently taken down at each pick-up location. 
It is therefore desirable to keep the size and weight of cameras for 
portable pick-up work at a minimum. In some cases a sacrifice in 
view-finder performance has been made to permit a reduction in the 
size and weight of the camera. Some portable cameras which em- 
ploy one of the more complicated view-finders are construced so that 
the camera can be separated into two units. This construction not 
only makes the camera more portable but also makes it possible to 
mount the two parts separately on the tripod. 



LENS- 



^MIRROR 

~ A 
'X r 

= XY\ 

rB 



MOSAIC- B 



VIEWING 

TPERTURE 



\ 
II V 



// ICONOSCOPE 



I FOCUS 
CONTROL 



FIG. 1. Mirror arrangement for viewing the optical image 
on the mosaic of the pick-up tube. 






Since the view-finders in group No. 1 require fewer parts, occupy 
less space, and contribute less weight, they are more acceptable from 
the standpoint of requirement No. 5 than those in group No. 2. 

Descripton of Individual View- Finders. The following is a list 
of the view-finders which will be described. 

(1) Mirror arrangement for observing the optical image on the mosaic of the 
pick-up tube. 

(2} Semisilvered mirror arrangement for utilizing the camera lens to produce 
an optical image on a ground glass viewing-screen. 

(5) Kinescope or electronic view-finder. 

(4) Kinescope or electronic view-finder with remote focusing control. 

(5) Split image view-finder as used in the Contax and similar cameras. 

(6) Duplicate lens view-finder as used in the Rolliflex camera. 

(7) Combination duplicate lens and Kinescope view-finder. 



188 



G. L. BEERS 



[J. S. M. P. E. 



The first four view-finders in this list derive the view-finder image 
either directly or indirectly from the camera lens and are those which 
were previously classified as the group No. 1 view-finders. View- 
finders 5, 6, and 7 are the group No. 2 view-finders, and obtain the 
view-finder image from a separate optical system. For the sake of 
simplicity, the diagrams which will be used to illustrate the several 
view-finders will not show any means for either magnifying the 
optical image or for correcting it in the vertical and horizontal direc- 
tions. It is apparent that, if sufficient light is available, lens and 
mirror arrangements can be used to accomplish any of these results. 
The means for correcting for parallax is likewise omitted from the 
diagrams of the group No. 2 view-finders. Although the Iconoscope 



VIEWING 

'APERTURE. 




FIG. 2. Semisilvered mirror view-finder arrangement. 

is shown as the pick-up tube in each of the diagrams it is obvious 
that the Orthicon or any other type of pick-up tube may be used. 

Mirror Arrangement for Viewing the Optical Image on the Mosaic of 
the Pick- Up Tube. This is the original Iconoscope camera view- 
finder arrangement. It is illustrated by the diagram in Fig. 1. 
With this view-finder the cameraman, through the use of mirror A, 
observes on the mosaic B the optical image which is produced by the 
camera lens C. The shape of the glass envelope of the pick-up tube 
is usually such that only a portion of the image on the mosaic can be 
observed through the use of this system. The mosaics of the more 
recent pick-up tubes have very poor light-reflecting properties and 
the optical image produced on the mosaic is therefore unsatisfactory 
from the brightness standpoint. The chief advantage of this arrange- 
ment is its simplicity. It requires a minimum of equipment since it 



Mar., 1943] 



FOCUSING VIEW-FINDER PROBLEM 



189 



makes use of only the camera lens and does not employ a separate 
viewing-screen. No special adjustments are necessary when chang- 
ing either the camera lens or the pick-up tube. It has, however, all 
the limitations previously mentioned in connection with the group 
No. 1 view-finders. 

Semisilvered Mirror Arrangement Utilizing the Camera Lens to 
Produce an Optical Image on a Ground Glass Viewing Screen. The 
diagram in Fig. 2 illustrates this view-finder system. It makes use 
of a semisilvered mirror A to reflect some of the light transmitted by 
the lens B. This light is again reflected by the mirror C to produce 
an optical image on the ground-glass viewing screen D. In the experi- 
mental work on this arrangement mirrors were used in which the 



\-ENS 




FIG. 3. Kinescope or electronic view-finder. 



reflected light varied from 15 per cent to 40 per cent. Since the 
total light reflected from the front-surface mirror A is a compara- 
tively small percentage of the light passing through the mirror, the 
light reflected from the back surface of the mirror may be a fairly 
large percentage of the total reflected light. It is therefore necessary 
to use either a very thin mirror or else have the back surface of the 
mirror coated with a non-reflecting film, otherwise the light reflected 
from the back surface produces an image which is sufficiently dis- 
placed from the front surface image to reduce the effective resolution 
of the view-finder to a point where it is definitely unsatisfactory. 

The chief advantage to be found in this view-finder likewise lies 
in its relative simplicity. With respect to the arrangement shown 
in Fig. 1, it has the advantages of giving a somewhat brighter image 



190 G. L. BEERS [J. s. M. p. E. 

and also will provide a view of the scene whose area is greater than 
that included in the field of the camera. 

The most serious disadvantage of this view-finder arrangement is 
that it robs light from the mosaic of the pick-up tube and therefore 
decreases the effective light sensitivity of the system. Although it 
meets requirement No. 2 it has the other limitations of the group 
No. 1 view-finders. Since a separate ground glass viewing screen is 
used with this arrangement it is necessary to adjust the position of 
the viewing screen when changing pick-up tubes so that the viewing 
screen is the same distance from the optical center of the lens as the 
mosaic of the pick-up tube. This view-finder arrangement also 
imposes a limitation on the shortness of the focal length of the 
camera lens which can be used. 

Kinescope or Electronic View-Finder. This view-finder arrange- 
ment is obtained by incorporating in the camera a Kinescope on 
which is reproduced the television image. It is illustrated by the 
diagram in Fig. 3. 

The chief advantage of this view-finder system is that the relative 
brightness of the view-finder image does not diminish as the sensi- 
tivity of the pick-up tube is increased. The brightness of the 
Kinescope view-finder image is determined primarily by the char- 
acteristics of the Kinescope which is used and the operating voltages 
which are employed. It, like the view-finder arrangements illus- 
trated in Figs. 1 and 2, does not necessitate any view-finder adjust- 
ments when either pick-up tubes or camera lenses are interchanged 
and no correction for parallax is required. 

In addition to the several limitations discussed in connection with 
the group No. 1 view-finders the Kinescope type of view-finder has 
the further restriction that the sharpness of the view-finder image is 
dependent on the resolution of that portion of the television system 
which it includes. It is therefore necessary that satisfactory elec- 
trical focus of the Kinescope be maintained for this view-finder to 
function satisfactorily. The space required in a camera to house this 
type of view-finder is relatively large. The several thousand volts 
which are used as anode supply for the Kinescope presents a problem 
in providing a satisfactory camera cable. If this camera cable 
problem is avoided by incorporating a voltage supply unit in the 
camera, a corresponding increase in the size and weight of the camera 
results. 

Kinescope or Electronic View- Finder with Remote Focusing Control. 



Mar., 1943] 



FOCUSING VIEW-FINDER PROBLEM 



191 



In the Kinescope view-finder arrangement just described a television 
monitoring unit with its Kinescope is in effect moved from its normal 
location so that it can be associated directly with the focusing control 
in the camera. In the remote control form of the Kinescope view- 
finder the physical location of the parts is reversed and a remote 
camera focusing control is provided that can be used at the normal 



MOTOR 




Fit 



VIEWING 
AvPERTURE 



FOCUS 
CONTROL 



Kinescope or electronic view-finder with remote 
focusing control. 



location of the television monitoring unit. The diagram in Fig. 4 
illustrates this arrangement. As indicated in the diagram the re- 
mote control of focus is accomplished through the use of selsyn 
motors. 

The chief advantage of this view-finder system lies in the fact that 
it permits a camera which is small in size and light in weight. This 
is especially desirable in portable pick-up work. It makes possible a 
camera which is particularly suitable for locations which are in- 



192 



L. BEERS 



[J. S. M. P. E. 



accessible to a cameraman. It also provides the advantages which 
have been discussed in connection with the previous Kinescope view- 
finder. With the remote focusing arrangement the only view-finder 
equipment which must be housed in the camera is the small selsyn 
motor. A wire frame view-finder mounted on the side of the camera 
is used by the cameraman to keep the camera trained on the desired 
scene. The focusing is done by a control operator at the monitoring 
unit. 

In addition to the deficiencies of the Kinescope view-finder illus- 
trated by Fig. 3 this arrangement has the further limitation that a 
fairly high degree of coordination is required between the man who is 
panning the camera and the man at the remote point who is oper- 



SPLIT- IMAGE. 
RANGE FINDER 




VIEWING 
APERTURE. 



l-EN 



FOCUS 
CONTROL 



FIG. 5. Split image view-finder. 

ating the focusing control. When the focusing and panning are done 
by the same individual he subconsciously starts to adjust the focusing 
control in the proper direction to correct for any change in distance 
between the camera and the desired scene. 

Split Image View- Finder as Used in the Contax and Similar Cam- 
eras. The diagram in Fig. 5 illustrates this type of view-finder. It 
utilizes an optical system which is actuated by the focusing control 
simultaneously with the camera lens and produces two optical images 
which are accurately superimposed when the camera lens is in focus 
on a desired object or scene. The two images are displaced with 
respect to each other when the focusing control has not been properly 
adjusted. In a view-finder of this type which was investigated, the 
condition of focus could be accurately determined only in a small 
area in the center of the picture. Another limitation of this par- 



Mar., 1943] 



FOCUSING VIEW-FINDER PROBLEM 



193 



ticular view-finder was that when using long focal length lenses the 
actual size of an object in the view-finder remained the same as when 
a short focal length lens was used. A hair-line indicator was pro- 
vided to indicate the smaller field covered by the longer focal length 
lens. An adjustment is required with this type of view-finder when 
interchanging pick-up tubes so that the optical system of the view- 
finder is adjusted to compensate for variations in the position of the 
mosaic in different pick-up tubes. 

Duplicate Lens View-Finder as Used in the Rolleiflex Camera. The 
diagram in Fig. 6 illustrates this view-finder arrangement. As shown 
in this diagram an auxiliary lens A , which has the same focal length 
as the camera lens B, is used to produce on the ground-glass C an 



VIEW- FINDING 
LENS- A 




FIG. 6. Duplicate-lens view-finder. 

optical image which corresponds to the optical image on the mosaic D 
of the pick-up tube. The position of the ground-glass C, with re- 
spect to the optical center of the lens A, must always correspond to 
the position of the mosaic D with respect to the lens B. The two 
lenses must be matched accurately for focal length. To facilitate 
interchanging lenses of different focal lengths each pair of lenses is 
usually assembled on a single mounting plate. This view-finder 
system provides an image of a portion of the area outside that 
covered by the field of the camera. A view-finder of this type 
provides a very accurate indication of focus under all conditions 
since the view-finder lens can be kept wide open when the camera 
lens is stopped down. Since a fast lens is normally used to provide 
the view-finder image the brightness of this image has been relatively 
satisfactory. The increased sensitivity of pick-up tubes, however, 



194 G. L. BEERS [J. S. M. P. E. 

is causing the image brightness obtained from this view-finder system 
to decrease to the point where it no longer will be satisfactory. Some 
system for parallax t correction is required with this type of view- 
finder. The amount of correction which is necessary is generally 
determined by the maximum diameter of the lenses supplied with 
the camera. 

The inability of this view-finder to meet the ideal view-finder 
requirements is found in connection with requirements No. 4 and 
No. 5. Since a separate lens is used to produce an optical image on a 
ground-glass screen the position of this screen must be adjusted to 
correspond to that of the pick-up tube mosaic whenever pick-up 
tubes are interchanged. Since the longer focal length lenses (20-in. 
//4.5 lenses are frequently used) are large and heavy, the additional 
lens required for this view-finder not only makes the problem of inter- 
changing lenses more difficult but materially increases the overall 
size and weight of the camera. 

Combination Duplicate Lens and Kinescope View-Finder. It has 
previously been pointed out that as the sensitivity of the television 
pick-up tube is increased, a corresponding decrease occurs in the 
relative brightness of the image in an optical view-finder. At present, 
when the maximum sensitivity of the Orthicon pick-up tube is 
utilized, the image brightness obtained from an optical view-finder, 
such as the duplicate lens arrangement previously described, is on 
the verge of being unsatisfactory. With the Kinescope type of view- 
finder any increase in the sensitivity of the pick-up tube is auto- 
matically compensated as far as the brightness of the view-finder 
image is concerned. The types of Kinescope view-finders which have 
been described, however, do not meet performance requirements No. 
1 and No. 2. If a further improvement is made in the sensitivity of 
television pick-up tubes, it may be necessary to use a view-finder of 
the type illustrated in Fig. 7. 

In this diagram it will be noted that two pick-up tubes are used 
with a pair of duplicate lenses. Associated with the camera pick-up 
tube are the normal television amplifier and deflection circuits. The 
amplifier used with the view-finder pick-up tube is designed to pass 
a wider frequency band than is normally required by the television 
system. The increase in resolution, which the wider frequency band 
permits, enables this view-finder to provide a more accurate indi- 
cation of focus than could be obtained from the previous Kinescope 
view-finders. Since a separate view-finder lens is employed it can 
always be used at its maximum aperture even though the camera 

i.<? stnnnpH Hnwn anH tVins: -nrn\riHp at all timp<5 pn anntratp inrli- 



Mar., 1943] 



FOCUSING VIEW-FINDER PROBLEM 



195 



cation of the proper focus adjustment. The deflection circuits for 
the view-finder pick-up tube are so arranged that a slightly greater 
area of the scene is scanned than is the case with the camera pick-up 
tube. 

The deficiencies of this view-finder from the standpoint of the ideal 
view-finder are in respect to the requirements No. 4 and No. 5 which 
deal primarily with operating convenience. With reference to re- 
quirement No. 4, when pick-up tubes are interchanged, the position 
of one of the pick-up tubes must be adjusted so that the mosaics of 
the two tubes are the same distance from their respective lenses. The 
electrical focus of both the view-finder pick-up tube and Kinescope 
must be kept in proper adjustment for this view-finder to function 
satisfactorily. The extra equipment required for this type of view- 



VIEW FINDING 
UENS 




LENS 



FIG. 7. 



Combination duplicate-lens and Kinescope 
view-finder. 



finder materially increases the size and weight of a television camera. 

Comparison of the Individual View- Finders. The chart on p. 182 
shows the ideal view-finder requirements that are met by the several 
view-finders which have been described. The wording used in the 
chart for each of the requirements is such that a yes in the column 
beneath a given view-finder indicates that it meets the specified re- 
quirement. 

Conclusions. It is apparent that none of the view-finders which 
have been described meets all the requirements of an ideal view- 
finder. The relative importance of some of the requirements is 
determined to a considerable extent by whether the camera is in- 
tended for studio or outdoor pick-up work. In general, the duplicate- 
lens type of view-finder has given the most satisfactory results. If 
it is desired to keep the size and weight of the camera as near the 
minimum as possible, the Kinescope view-finder with remote focusing 






196 G. L. BEERS 

control is a practical arrangement. A substantial increase in the 
sensitivity of television pick-up tubes will result in more consider- 
ation being given to the several types of Kinescope view-finders. 

In this discussion no reference has been made to the relative cost 
of the various view-finder arrangements. For the time being, at 
least, the cost of television pick-up equipment has been considered 
to be of secondary importance to performance and operating con- 
venience. 

The writer wishes to acknowledge the individual and cooperative 
efforts of numerous RCA and NBC engineers who have contributed 
to the solution of the view-finder problem. 



FIFTY-THIRD SEMI-ANNUAL MEETING 



OF THE 



SOCIETY OF MOTION PICTURE ENGINEERS 



HOTEL PENNSYLVANIA, NEW YORK, N. Y. 
MAY 4th-6th, INCLUSIVE 



Officers and Committees in Charge 

HERBERT GRIFFIN, President 

EMERY HUSE, Past-President 

LOREN L. RYDER, Executive V ice-President 

E. ALLAN WILLIFORD, Secretary 

D. E. HYNDMAN, Engineering Vice-President 

W. C. KUNZMANN, Convention Vice-President 

A. C. DOWNES, Editorial Vice-President 

ALFRED N. GOLDSMITH, Chairman, Local Arrangements Committee 

SYLVAN HARRIS, Chairman, Papers Committee 

JULIUS HABER, Chairman, Publicity Committee 

J. FRANK, JR., Chairman, Membership Committee 

H. F. HEIDEGGER, Chairman, Convention Projection Committee 

Reception and Local Arrangements 

ALFRED N. GOLDSMITH, Chairman 
M. BENNETT J. A. HAMMOND P. A. McGuiRE 

L. A. BONN M. HOBART J. A. NORLING 

M. R. BOYER C. F. HORSTMAN H. RUBIN 

J. C. BURNETT L. B. ISAAC E. I. SPONABLE 

A. S. DICKINSON E. W. KELLOGG J. H. SPRAY 

G. FRIEDL, JR. J. H. KURLANDER R. O. STROCK 

W. E. GREEN J. A. MAURER H. E. WHITE 

Registration and Information 

E. R. GEIB F. HOHMEISTER 

J. FRANK, JR. P. K. SLEEMAN 



J. W. DAVEE 

P. C. GOLDMARK 

R. F. MITCHELL 



Hotel and Transportation 

O. F. NEU, Chairman 
M. W. PALMER 
P. D. RIES 
C. Ross 



J. A. SCHEICK 

F. C. SCHMID 

E. S. SEELEY 



197 



198 SEMI- ANNUAL MEETING [J. S. M. P. E. 

Publicity Committee 

JULIUS HABER, Chairman 

H. DESFOR C. R. KEITH P. A. McGuiRE 

C. R. DAILY S. HARRIS H. SHERMAN 

Luncheon and Banquet 

D. E. HYNDMAN, Chairman 

M. R. BOYER A. N. GOLDSMITH E. I. SPONABLE 

J. C. BURNETT O. F. NEU J. H. SPRAY 

A. S. DICKINSON M. W. PALMER E. A. WILLIFORD 

Projection Committee 

H. F. HEIDEGGER, Chairman 

M. BENNETT H. HOLLENDER A. L. RAVEN 

L. W. DAVEE J. J. HOPKINS P. D. RIES 

J. K. ELDERKIN C. F. HORSTMAN J. E. ROBIN 

W. W. HENNESSY L. B. ISAAC H. RUBIN 

Officers and Members of New York Projectionists Local No. 306 

Hotel Reservations and Rates 

Hotel Rates. The Hotel Pennsylvania management extends to SMPE dele- 
gates and guests the following per diem rates, European plan : 

Room with bath, one person $3 . 85-$7 . 70 

Room with bath, two persons, double bed $5. 50-$8. 80 

Room with bath, two persons, twin beds $6 . 60-$9 . 90 

Parlor suites: living room, bedroom, and bath $10 .00, 11. 00, 13 . 00 ; 

and 18.00 

Reservations. Early in April Hotel room-reservation cards will be mailed to all 
the members of the Society. These cards should be returned to the Hotel as 
promptly as possible in order to be assured of accommodations. 

Due to the great influx of wartime visitors to New York it is often very diffi- 
cult to obtain accommodations, and for that reason reservations should be made 
well in advance of the meeting dates. It will not be possible to guarantee accom- 
modations if reservations are not made in advance. 

Registration. The registration headquarters for the Fifty-Third Semi-Annual 
Meeting will be on the 18th floor of the Hotel, at the entrance of the Salle Moderne, 
where the technical sessions will be held. All members and guests attending the 
meeting are expected to register and receive their identification cards and badges 
required for admission to all the sessions. 

Technical Sessions 

The Papers Committee is assembling an attractive and interesting program of 
papers for the Meeting, the details of which will be published in a later issue of 
the JOURNAL. Members and others who are contemplating the preparation of 



Mar., 1943] SEMI-ANNUAL MEETING 199 

papers should communicate immediately with the Chairman of the Papers Com- 
mittee, at the office of the Society in.the Hotel Pennsylvania, New York, N. Y. 

The assistance of the membership of the Society is earnestly sought by the 
Committee in the work of soliciting papers, and suggestions as to possible presen- 
tations and authors will be gratefully received. 

Fifty-Third Semi- Annual Banquet and Informal Get -Together Luncheon 

The usual Get-Together Luncheon for members, their families, and guests will 
be held in the Roof Garden of the Hotel on Tuesday, May 4th, at 12 : 30 P. M. 

The Fifty-Third Semi-Annual Banquet and Dance will be held in the Georgian 
Room of the Hotel on Wednesday, May 5th, at 8: 00 P. M. an evening of sociabil- 
ity and dancing. 

[TENTATIVE PROGRAM 
Tuesday, May 4th 

9:00 a.m. Hotel Roof; Registration 

10:00 a.m. Salle Moderne; Business and Technical Session 
12: 30 p.m. Roof Garden; SMPE Get-Together Luncheon for members, their 
families, and guests. Addresses by eminent speakers, names to be 
announced later 
2 : 00 p.m. Salle Moderne; Technical Session 

The evening of this date will be left open 

Wednesday, May 5th 

9:30 a.m. Hotel Roof; Registration 

10:00 a.m. Salle Moderne; Technical Session 

12 : 30 p.m. Luncheon Period 

2 : 00 p.m. Salle Moderne; Technical Session 

8:00 p.m. Georgian Room; Fifty-Third Semi- Annual Banquet and Dance 

Thursday, May 6th 

9:30 a.m. Hotel Roof; Registration 

10:00 a.m. Salle Moderne; Technical Session 

12: 30 p.m. Luncheon period 

2:00 p.m. Salle Moderne; Technical Session 

Miscellaneous 

Motion Pictures. The identification cards issued at the time of registering will 
be honored at a number of de luxe motion picture theaters in the vicinity of the 
Hotel. Many entertainment attractions are available in New York to out-of- 
town delegates and guests, information concerning which may be obtained at the 
Hotel information desk or at the registration headquarters. 

Parking. Parking accommodations will be available to those motoring to the 
meeting at the Hotel garage, at the rate of $1.25 for 24 hours and in the open lot 



200 SEMI- ANNUAL MEETING 

at 75 cents for day parking. These rates include car pick-up and delivery at the 
door of the Hotel. 

Note: The 1943 Spring Meeting is subject to cancellation if later deemed ad- 
visable in the national interest. 

W. C. KUNZMANN 
Convention Vice- President 



IMPORTANT 

Hotel registration cards must be re- 
turned immediately. Otherwise the 
Hotel can not guarantee accommoda- 
tion, on account of the large influx of 
visitors to New York. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 



VOLUME XL ... APRIL, 1943 
: 



CONTENTS 

PAGE 

Frequency Modulation Distortion in Loud Speakers 

G. L. BEERS AND H. BELAR 207 

Some Recent Developments in Record-Reproducing 

Systems G. L. BEERS AND C. M. SINNETT 222 

Current Literature 242 

Fifty-Third Semi- Annual Meeting, Hotel Pennsylvania, 

New York, N. Y., May 4-6, 1943 244 

Officers and Governors of the Society 248 

Committees of the Society 25.1 

Constitution and By-Laws of the Society 256 



(The Society is not responsible for statements of authors.) 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

SYLVAN HARRIS, EDITOR 
ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
**President: HERBERT GRIFFIN, 

90 Gold Street, New York, N. Y. 
** Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
** Executive Vice-f 'resident: LOREN L. RYDER, 
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^Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Avenue, New York, N. Y. 
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Box 6087, Cleveland, Ohio. 
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Governors 

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**WILLIAM A. MUELLER, Burbank, Calif. 

*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
**H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
* "JOSEPH H. SPRAY, 1277 E. 14th Street, Brooklyn, N. Y. 
**REEVE O. STROCK, 195 Broadway, New York, N. Y. 

*Term expires December 31, 1943. 
**Term expires December 31, 1944. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motion 
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Published monthly at Easton, Pa., by the Society of Motion Picture Engineers. 

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General and Editorial Office, Hotel Pennsylvania, New York, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1943, by the Society of Motion 

Picture Engineers, Inc. 



FREQUENCY MODULATION DISTORTION 
IN LOUD SPEAKERS* 



G. L. BEERS AND H. BELAR** 



Summary. As the frequency-response range of a sound-reproducing system is 
extended the necessity for ^minimizing all forms of distortion is correspondingly in- 
creased. The part that the loud speaker can contribute to the overall distortion of a 
reproducing system has been frequently considered. A type of loud speaker distortion 
that has not received general consideration is described. This distortion is a result of 
the Doppler effect and produces frequency-modulation in loud speakers reproducing 
complex tones. Equations for this type of distortion are given. Measurements con- 
firming the calculated distortion in several loud speakers are shown. An appendix 
giving the derivation of the equations is included. 

Distortion in its several forms is undoubtedly the most serious 
problem with which the engineer has to deal in the design of a satis- 
factory high-fidelity sound-reproducing system. An early apprecia- 
tion of the importance of minimizing distortion in such a system was 
obtained in development work on high-fidelity radio receivers dur- 
ing the period from 1930 to 1935. At that time an experimental 
radio receiver was developed which gave an overall distortion from 
modulated radio-frequency input to audio-frequency output at the 
loud speaker terminals of two to three per cent arithmetic sum of all 
harmonics. During the development of this receiver consideration 
was given to the part which the loud speaker might contribute to the 
overall distortion in a sound-reproducing system. The possibility 
of a loud speaker, reproducing a complex wave, creating frequency 
modulation distortion by virtue of the Doppler effect was suggested. 
However, no facilities were available at that time to determine the 
extent of this type of distortion. 

In the past few years frequency modulation broadcasting and im- 
proved record-reproducing systems have renewed the interest in high- 
fidelity sound reproduction. During a recent review of the distor- 

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received Dec. 
20, 1942. 

** RCA Manufacturing Company, Inc., Camden, N. J. 

207 



208 G. L. BEERS AND H. BELAR [j. s. M. P. E. 

tion problem, a mathematical and experimental investigation of 
the possibility of frequency modulation distortion in loud speakers 
was conducted. It is the purpose of this paper to record the results 
of this investigation. 

Theoretical Considerations. A loud speaker cone mounted on a 
flat baffle may have to move through a relatively large distance at 
low frequencies to produce even a small acoustic output. If such a 
loud speaker cone is simultaneously radiating both a low and a high- 
frequency the source of high-frequency energy can be considered as 
moving back and forth in space and the high-frequency energy will 
therefore be frequency modulated. This modulation in frequency is 
due to the Doppler effect and can be analyzed by assuming the speaker 
to be a constant-tone generator of the modulated frequency which is 
being displaced along the axis of the cone at the rate and amplitude 
of the modulating frequency. The resulting frequency-modulated 
wave can be represented by a "carrier" and an infinite number of 
side-bands. The fundamental or carrier is of constant amplitude and 
frequency. Its amplitude is less than that of the original wave and 
depends upon the degree of modulation. The side-bands are located 
symmetrically about the carrier and are spaced at intervals equal to 
the modulating frequency. The distortion introduced by these side 
bands can be expressed by a distortion-factor. Along the axis of a 
cone speaker this distortion-factor can be stated as follows : 
distortion-factor = 0.033 Aifa per cent 

where AI = amplitude of cone motion (each side of mean position) in inches at 

the modulating frequency. 
/2 = modulated frequency. 

d.f. = distortion factor in per cent, defined as the square-root of the ratio 
of power in the side-bands to total power in the wave. 

As shown in Appendix II, the amplitude of the cone motion re- 
quired to radiate a given acoustic power varies inversely with the 
square of the frequency and inversely with the square of the diameter 
of the speaker cone. 

The amplitude of the cone motion is likewise proportional to the 
square root of the audio-frequency power supplied to the loud speaker. 
A 12-inch cone on an infinite baffle working with both sides, in air re- 
quires a motion through a peak amplitude of approximately Vie inch 
(each side of its mean position) to radiate one acoustic watt at 100- 
cycles. Thus it can be said that a 12-inch cone radiating one acous- 
tic watt at 100 cycles simultaneously with a 5000-cycle signal will 



April, 1943 J FREQUENCY MODULATION DISTORTION 209 

distort the 5000-cycle signal by approximately 10 per cent due to fre- 
quency modulation. An 8-inch cone could radiate only 0.20 watt 
at 100-cycles for the same distortion at 5000-cycles and only 0.012 
watt at 50-cycles for the same distortion limit. 

The distortion-factor, for any other low frequency /i, cone size and 
power radiated, is given by the following formula; assuming a flat 
baffle with the cone radiating on both sides: 



distortion-factor = 2900 per cent 



where fz modulated frequency, 

/i = modulating frequency. 

PI = acoustic power output at /i in watts. 

d = cone diameter in inches. 

Comparisons with Similar Forms of Distortion. A distortion similar 
to frequency modulation of complex tones in loud speakers occurs 
in the reproduction of sound from film, due to sprocket-hole modula- 
tion, and in disk reproduction due to tracking angle. In the case of 
film reproduction a distortion-factor of 10 per cent would be had with 
an unfiltered sound gate reproducing a 400-cycle signal with a 1-mil 
displacement at sprocket-hole frequency. In the case of a disk re- 
producer 10 per cent distortion would be had with a straight TY-i-inch 
tone-arm reproducing a 5000-cycle note simultaneously with a 100- 
cycle note of 0.5- mil amplitude. 

Distortion Measurements. In making distortion measurements on 
several loud speakers the following procedure was followed. The 
speaker under test was set up in the sound measuring room and fed 
with a variable-frequency from the measuring channel. In series 
with this signal, right at the voice coil, was also introduced a low- 
frequency signal from another oscillator. The resultant complex 
sound was picked up by a ribbon microphone two feet from the 
speaker and on the axis of the cone. The output of the microphone 
was fed to a distortion-factor meter through a high-pass filter which 
eliminated the low-frequency signal. In the distortion-factor meter 
the modulated or distorted signal from the variable-oscillator was 
balanced against a portion of the same frequency fed there directly 
from the variable oscillator. The phase and amplitude of the balanc- 
ing signal were adjusted until a minimum reading was obtained. The 
residual reading represented the root-mean-square voltage of all forms 
of distortion, terms which may be simple harmonic distortion, cross- 



210 



G. L. BEERS AND H. BELAR 



LT. S. M. P. E. 



modulation due to nonunifortnity of flux-density in the air-gap, 
frequency modulation distortion, or any other forms of distortion. 
To eliminate the effect of noise, readings of noise were taken and 











HARMONIC.- CROSS MODULATION,- AND F. M.'oiSYoRTIO 


i. 


























1' 


: i 


NCH 


S 


pe 


AKS 


R 


























































































































SINGLE FREQUENCY 












DISTORTION WITH TWO 
FREQUENCIES. INPUT 














INPUT TO VOICE COU-""" 
t. (APPRO*. VIS WATT.) 










0.5 
0.5 

FRE 


,/OL.- 

s/ou- 
<5- 


r 60~ AND 

r VARIABLE 








g 




































** 








I 
















































E 






























































































/ 
















































/ 


t- 
2 








































1 \ 




^ 






























'< 


-1 fv 












' ^ 


A.UC. 

M- DIST. 










\. 














s 


, 


S"^ 


1 \ f -" 




" / 


i 


*< 


f r 


- 


^ 


| 












^v 


1 










S 








S 


*- 


y 


4 


\ 







































' 














^ 






to 1OO 2oo 5OO 


1000 2000 


SOOO 101 



FIG. 1. Frequency modulation distortion for conventional 12-inch cone speaker. 













HARMONIC - 


CROSS MODULATION ,- AND F.M.- DISTORTION. 




























61 


'4C^ 


C 


iN 


E 


w 


TH 


-o 


-B 


e 


3 


HORN 






















































































\ 






































Dl 
TV 

IN 


5TORTION WIT 
FREQUENCE 
PUT, 2.5VOL.TJ 
60~ AND 2.S 


K 

i 






\ 
















































































T 


M 


IK 


vBL 


: f 


RI 

\ 








\ 


















































^rl 




V- 






, 




















































4 








\ 


















































z 




































/ 


\ 














1 


L ^ 


Z, 


p 










DISTORT ON' 
FREQUENCY 


Wl 
NF 
") 


fH SINGLE 
UT. 












7 


\ 














/ 


^ 


5 


p 










i (APPR 

X. 


OX. ( 

1 


).4v 


















/ 


















Jf 


CALC 
RM.III51 
O.OZ2IK 
BIST. 


D 












2 






















/ 






V 








^ 


^ 


f 














"** 


x 














- 


- 


' 










W^ 


g 




-^ 



























X 








- ~ 


.. 








^ 


-^ 
















































- 


MM 





-- 


SS " 






V 












I 


- 


^^ 



100 200 



FTG. 2. Frequency modulation distortion for 6-inch cone in folded horn. / 

measurements of distortion made only over the range for which noise 
was not a factor. 

The effect of harmonic distortion was isolated by making distor- 
tion measurements with a single-frequency input at the same level. 
Objections can be raised against using a single microphone in a single 



^pril,jl943] FREQUENCY MODULATION DISTORTION 



211 



, .position for distortion measurements. Any one reading of distor- 
tion is subject to error due to the uneven distribution of sound in a 
room. However, in this case, a number of readings were taken at 
various frequencies which together should show the trend of the dis- 
tortion characteristics. If allowance is made for noise and harmonic- 
distortion the remaining distortion of a complex sound would be 
made up of both cross-modulation and frequency modulation. 
Since both produce side-bands of the same frequencies they can not 
be separated easily for any one reading, but the amount due to each 
can be determined by measuring the distortion at various frequencies. 
The cross-modulation distortion should be proportional to the ampli- 







FIG. 3. Characteristics of 6-inch cone speaker of folded-edge type. 

tudes and should therefore be independent of frequency, whereas the 
frequency modulation distortion should be proportional to the fre- 
quency because the phase shift at shorter wavelengths is greater for 
the same mechanical displacement. Measurements were made of the 
mechanical displacement of the cone by means of a depth-gauge 
which wasj ad justed to touch a small aluminum cone fastened to the 
voice-coirfor the purpose of this measurement. 

It should be noted that the power input to the loud speakers which 
was used in making the measurements of frequency modulation dis- 
tortion was 0.5 watt or less. Since all but the smallest table-model or 
portable receivers are capable of supplying power outputs in exess of 
this value it is apparent that the measurements are indicative of con- 
ditions which are actually met in practice. In the case of loud speak- 



212 



G. L. BEERS AND H. BELAR 



[J.S. M. P. E. 



ers used in public-address systems and in theaters the power used is 
many times this value. 

The calculated frequency modulation distortion for the measured 
amplitude of cone displacement is shown on Fig. 1 for a conventional 
12-inch cone speaker. It may be noted that at 5000 cycles and above 
frequency modulation distortion begins to have an effect; the cal- 
culated amount being 4 per cent at 6000 cycles. The measured 
amount follows the curve except that at 7000 cycles the measured 
distortion is much higher than that calculated. This may be ex- 
plained by the fact that for the calculated frequency modulation dis- 
tortion, uniform response and a dead auditorium has been assumed. 
Frequency modulation of an audio wave becomes more noticeable 



MEASURED DISTORTION M.L. CAUSES TWO FREQUENCIES 
INPUT 0.5 VOLT VARIABLE PBE9; VOLT feO~ CON STANT.--) 




FIG. 4. Characteristics of 12-inch permanent-magnet speaker. 



in a live room. In such a room the pattern of standing waves is con- 
tinuously shifted. Thus, small changes in phase can produce large 
changes in amplitude, thereby converting frequency modulation 
into amplitude-modulation. 

Similar results were obtained with a 6-inch cone in a folded horn as 
shown in Fig. 2. Compared with the 12-inch speaker this horn and 
cone combination has less distortion below 100 cycles probably due 
to the loading of the horn. Otherwise the same rise in overall dis- 
tortion is noted at the high frequencies and which may be accounted 
for by frequency modulation. However, at 2000 cycles the particular 
unit tested had considerable cross-modulation distortion. 

The characteristics of a 6-inch cone speaker of the folded-edge type 
are shown in Fig. 3. The distortion with a single tone is low at high 
frequencies but is always high when two tones are reproduced simul- 
taneously. There is a trend toward greater distortion at higher fre- 



April, 1943] FREQUENCY MODULATION DISTORTION 



213 



quencies in accordance with the calculated frequency modulation dis- 
tortion. The modulating frequency in this case was 100 -cycles. At 
60-cycles the distortion was too great to permit useful measurements. 

Another speaker which also had considerable cross -modulation dis- 
tortion in the midrange was a 12-inch permanent-magnet speaker. 
The characteristics of this speaker are shown in Fig. 4. The increase 
in the overall distortion with frequency, however, is still noticeable. 

In order to test the distortion of the measuring channel, distortion 
measurements were made with the distortion meter connected di- 
rectly across the voice-coil of the speaker. This distortion always 
measured less than 1 per cent. However, this did not preclude the 
possibility of distortion in the microphone. 























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FIG. 5. Distortion characteristics of speaker with separate high and low- 
frequency units. 

The latter is usually assumed to have very low distortion. This 
was further verified by tests made on a combination speaker which 
employed separate high and low-frequency units and which should 
have very low cross-modulation and frequency modulation distortion. 
Measurements, as shown in Fig. 5, confirm this conclusion. The 
mid-frequency and high-frequency distortion with complex tones, 
with the exception of one point, is less than 2 per cent. The low- 
frequency distortion with a single tone showed a peak at 90 cycles 
but below that frequency the distortion is less than that of other 
speakers tested. 

The frequency modulation distortion should be independent of the 
amplitude of the modulated frequency but be directly proportional 
to the amplitude of the modulating frequency. Thus if 5000-cycles 
and 60-cycles are reproduced together the per cent distortion of the 



214 



G. L. BEERS AND H. BELAR 



[J. S. M. P. E. 



5000-cycle wave due to frequency modulation should be independent 
of the amplitude at 5000 cycles but should be directly proportional to 
the amplitude of motion at 60 cycles. This is borne out by measure- 
ments shown in-Figs. 6 and 7. Fig. 6 shows the measured distortion 
with the 60-cycle input varied. The increase in distortion with 60- 



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FIG. 7. Distortion with modulated frequency varied in amplitude. 

cycle input may be noted. Fig. 7 shows the distortion for constant 
60-cycle input but with the amplitude of the 5000-cycle signal varied. 
The per cent distortion should remain constant according to calcula- 
tions, and the measurements confirmed this conclusion. 

Listening Tests. A question which naturally arises is : how audible 
is this form of distortion and how much of it can be allowed for vari- 
ous applications? 



April, 1943] FREQUENCY MODULATION DISTORTION 215 

I 

Listening tests were made as follows : The signal and the modulat- 
ing tone were applied to a speaker in the sound-measurement room 
and a microphone placed before it. The output of the microphone 
was fed to another speaker in another room through an amplifier and 
filter which eliminated the low-frequency modulating- tone. Thus 
the observer could not hear the low-frequency tone itself but only its 
effect upon the higher frequency. As expected and explained before, 
the audibility of distortion was considerably increased if the micro- 
phone were used to pick up a greater amount of reflected sound. The 
audibility varied but, in general, it can be said that a distortion of 
about 2 to 3 per cent becomes noticeable as a change in quality. The 
sensation produced is that of a very familiar form of distortion which 
is still hard to describe. The sound is just not clean. 

Considerable difficulty arises in endeavoring to evaluate the ob- 
jectionability of this distortion through listening tests involving the 
reproduction of speech and music. The most obvious method of ob- 
taining the desired information is by a comparison between a speaker 
which is producing the distortion and one which is not. For such a 
comparison to be of real value it is necessary not only that the per- 
formance characteristics of the two speakers be substantially identi- 
cal (except with respect to the frequency modulation distortion) but 
also that the distortion from all other sources be kept as low as pos- 
sible. Although preliminary listening tests have indicated the pres- 
ence of this distortion in the reproduction of music, the preference 
given other work, which at the present time is more essential, has pre- 
vented setting up the necessary facilities to conduct conclusive tests. 
It is hoped that these tests can be conducted in the near future. 

Means of Reducing Frequency Modulation Distortion of Complex, 
Tones. Some of the means of reducing the distortion are: 

(1) Reduce the amplitude of cone traverse by loading the speaker with a horn. 

(2} Increase the cone diameter and thus reduce amplitude of motion. 

(5) Limit the power input at low frequencies. 

(4) Use separate speakers for the low and high frequencies. 

The following example illustrates the reduction in distortion which 
can be obtained by the use of separate low and high-frequency 
speakers. The distortion of an 8-inch speaker in a flat baffle radiat- 
ing 0.1 watt at 50-cycles simultaneously with a 10,000-cycle signal 
would be 






216 G. L. BEERS AND H. BELAR tf. S. M. P. E. 

distortion-factor = 2900 f j^ = 2900 W '^ x ^ = 57 per cent approx. 
but if two 8-inch speakers were used divided at 



/ = tfft = -50 2 X 10,000 = 292 cycles 
the distortion under the assumed conditions would become : 



distortion-factor = 2900 "g? = 2900 = 1.7 per cent 

or a reduction of 34 : 1. 

It may be noted that consideration has been given only for the dis- 
tortion at a point along the axis of the cone. At right angles to the 
cone, frequency modulation of the type analyzed does not exist. In 
a normal listening- room, however, sound radiated along the axis will 
reach all points of the room because of reflections. A more accurate 
analysis would integrate the output of fundamental and side-bands 
for any position in the room. It was not thought necessary, however, 
to do this to illustrate the effect. 

Conclusions. Both mathematical analysis and measurements in- 
dicate the possibility of frequency modulation distortion in loud 
speakers when reproducing a complex sound-wave. Since this dis- 
tortion increases with frequency its effects are most pronounced in 
high-fidelity reproducing systems. It is fortunate that several rela- 
tively simple means can be employed to minimize or avoid this type 
of distortion. It is difficult to determine its seriousness on the basis 
of listening tests because it can not be isolated readily from other 
types of distortion. Although it is probable that this form of distor- 
tion is usually masked by distortion from other sources, nevertheless 
it is a factor which should be considered if the maximum in faithful 
sound reproduction is desired. 

APPENDIX 

Derivation of Equation for the Distortion Factor 
The equation for the Doppler effect is 1 



where v = velocity of sound in medium 
i>o = velocity of observer 
v a velocity of source 
f s = source frequency 
/o = observed frequency 



April, 1943] FREQUENCY MODULATION DISTORTION 217 

Let /i = frequency of motion of source 
/ 2 = source frequency 

Assume the motion of the source to be 

5 = AI sin 2irfit (2} 

The velocity of the source is 

S = 2-n-fiAi cos 2irfit 
Since the observer is at rest, VQ = and 

/i 



~ /2 ( 1 H ? ^ cos 2M ) (3) 

\ Xi / 

where v = fi\i (Xi being the wavelength of the wave of frequency /O and 2-irfiAi 
<*>. 

In a uniform sine wave, such as sin co t, the frequency is times the rate of 
change of the argument of the sine function, or 



If the sine function is not uniform, it is customary to define its instantaneous 
generalized frequency in an analogctn manner, as times the rate of change 
of the argument of the sine function. 2 ' 8 

fo = n~-r. (argument of sine function) 


so 

Argument of sine function = 2?r f fodt 



= 27T/2 f j 1 + ^ COS 27r/l/| dt 

= 27r/ 2 i H ^ - sin 2ir/i/ (5) 



since /i\ x = / 2 X 2 . 

The equation of a sound-wave along the axis of a cone speaker, for a single cone, 
can be written 



p = KA sin fat - ^) (5) 



218 G. L. BEERS AND H. BELAR U. s. M. P. E. 

where p = pressure 

K = a constant depending upon the speaker design 

A = amplitude of cone traverse 

/ = frequency 

X = distance from speaker 

X = wavelength of the sound 

According to the Doppler effect, the movement of the source causes the fre- 
quency of the sound at X to vary. Eq. 5 shows that the equation of the sound- 
wave, when the motion of the source is considered, is 

(7) 



where - is a constant phase-shift term which can be eliminated by choosing X 



The resultant equation is well known, and can be expressed in terms of its com- 
ponent frequencies by expansion in a series of Bessel functions as follows: 4 



p = KA t J 



Ji [sin 2(/ a + /0* - sin 2x(/ ~ fM 

J* (^) [sin 2*(/ + 2 /i)' 

- sin 



...( 



This means that the frequency-modulated wave consists of a fundamental or 
carrier which is constant and of frequency / but with the amplitude reduced by 

the factor 7 

Side-bands have been generated which are displaced from the carrier frequency 
by the amount of the frequency of motion of the source, and also by all the har- 
monics of this frequency as well. The amplitudes of the side-bands are propor- 
tional to Bessel functions having the same order as the side-band. 

The total power of the harmonic side-bands is proportional to 



(*) 

Since the total power of the wave is not changed by the frequency modulation 



April, 1943] FREQUENCY MODULATION DISTORTION 219 



whence 



The distortion-factor then becomes 
distortion-factor 



-Jl - [ 



where the distortion-factor has been defined as the ratio of the square root of the 
side-band power to the square root of the total power. 
Since 

X* X* X* 

~ ~ 



and the distortion-factor is approximately 



This approximation is very good for values of distortion up to 25 per cent. Since 
X^/ 2 = C, where C = 1130 ft/sec, the expression becomes 

distortion-factor = 0.707(2*) t ,{^' (100) per cent 

UdlfllZJ 

= 0.033/2^1 per cent (11) 

As shown in Appendix II, the amplitude of cone motion of a loud speaker for a 
given power radiated is inversely proportional to the square of the frequency and 
the square of the cone diameter, and likewise is directly proportional to the 
square root of the audio-frequency power supplied. 

- 

For a 12-inch cone working with both sides in air, and radiating one acoustic 
watt at 100-cycles, the amplitude of cone motion is approximately l /w inch.* This 
gives the equation for the distortion-factor as 

distortion-factor = 2900^^-* (12) 

** 



where d is in inches and PI is the acoustic power output in watts at /i cycles per 
second. 



220 G. L. BEERS AND H. BELAR [j. s. M. P. E. 

APPENDIX II 

Equation for the A mplitude of Motion of a Loud Speaker Cone 

The mechanical impedance of the air load upon one side of a vibrating piston 
set in an infinite baffle is 6 ' 7 



1 Jl(2KR)~] .TTUp jr / or rT>x 

I - KR + j^- 3 Ki(2KR) 



where R = radius of piston 

p = density of medium 

c = velocity of sound in medium 

K = 27T/X 

X = wavelength of sound 

CO = 27T/ 

/ = frequency, in cycles per second 

. Ji(2KR) = Bessel's function of first kind 
Ki(2KR) = modified Bessel's function 

By the series expansion for Bessel's function of the first kind, 

K'R* 



_ = _ 

KR 2 2 2 (3) " t "2 2 (3 2 )(4) * 

so the mechanical resistance is given approximately by 

(K 2 R* K*R* , K*R* ) 
TMA = ^ 2 p C j-2~ - 2H3) + 2^3*7(4) \ 

The power output is given by 

P = fMA^ 

where x = rms velocity of the piston. If the piston motion is given by 

x = A sin <t>t 
the velocity is 

x = Au cos (at 
The power output is therefore 

K*R* K*R , K'R* ) 
- - _ 



For low audio-frequencies when X R, the average power output is given by 
p _ wVpcAW. 

since the first -term of the series is much larger than succeeding ones and the aver- 
age value of cos 2 tat is one-half. 
Solving for A, the cone amplitude 



April, 1943] FREQUENCY MODULATION DISTORTION 221 

where K is a constant, / is the frequency in cycles per second, d is the cone diam- 
eter, and P is the radiated power. 

This formula is not accurate at high audio-frequencies since interference of the 
radiation from various parts of the disk occur in space, causing a departure from 
spherical wave propagation. 

REFERENCES 

1 OLSON, H. F.: "Elements of Acoustical Engineering," D. Van Nostrand Co., 
New York (1940), p. 16. 

2 HELMHOLTZ: "Die Lehre von den Tonempfindungen, " Braunschweig (1913), 
p. 649. 

3 CARSON, J. R.: "Notes on the Theory of Modulation," Proc. I. R. .. 10 
(Feb., 1922), p. 63. 

4 VAN DER POL: "Frequency Modulation," Ibid., 18 (July, 1930), p. 1199. 

6 FENDER, H., AND MC!LWAIN, K.: "Electrical Engineers' Handbook," John 
Wiley & Sons, New York (1936), Vol. V, 3rd ed. f p. 6 - 08 

6 RAYLEIGH: "Theory of Sound," The Macmillan Co., New York (1926). Vol. 
II, p. 164. 

7 Ref. 1, p. 80. 



SOME RECENT DEVELOPMENTS IN RECORD-REPRODUC- 
ING SYSTEMS* 

G. L. BEERS AND C. M. SINNETT** 



Summary. Several factors of importance in obtaining satisfactory reproduction 
of sound from lateral-cut phonograph records are considered. A n experimental record- 
reproducing system employing the principles of frequency modulation is described 
and data are supplied on the measured and calculated performance characteristics oj 
the system. Curves are included showing the vertical force required for satisfactory 
tracking with the experimental P.M. pick-up as compared with other pick-ups of 
conventional design. 

The remarkable increase in the sale of phonograph records during 
the past few years is a definite indication of the returning public 
interest in records as a medium of home entertainment. If the 
present interest in phonograph records is to be maintained, on a 
permanent basis, it is essential that the reproduction of sound from 
records be at least comparable to or preferably better than that 
which can be obtained from radio broadcasting. 

During the past few years, an investigation was conducted to 
determine the prospects of materially improving the overall per- 
formance of record-reproducing systems. One phase of the in- 
vestigation was directed toward the possibility of reproducing fre- 
quencies up to 10,000 or 12,000 cycles from standard shellac records 
without the introduction of objectionable surface noise. In the 
course of this investigation, the possibilities of producing a frequency- 
modulated signal by means of a special pick-up and associated 
circuits was investigated. This type of reproducing system appeared 
to lend itself to a realization of certain requirements which were 
considered essential to a satisfactory record-reproducing system. 
It is the purpose of this paper to discuss some of these requirements, 
to describe the frequency-modulation record-reproducing system, 
and indicate the improvement in performance which can be expected 
from such a system. 

* Presented at the 1942 Spring Meeting at Hollywood, Calif.; received Dec. 
15, 1942. 

** RCA Manufacturing Company, Inc., Camden, N. J. 
222 



RECORD-REPRODUCING SYSTEMS 223 

(A) PICK-UP REQUIREMENTS FOR SATISFACTORY REPRODUCTION OF 
LATERAL CUT RECORDS 

There are many factors which must be considered in the design 
of a pick-up to reproduce lateral-cut records. The following factors 
not only determine the quality of reproduction which will be obtained 
but also have a direct bearing on the life of the record and stylus. 

(1) Vertical Force Required for Satisfactory Tracking. The 
vertical force required for satisfactory tracking should be low enough 
to prevent excessive record wear and minimize record surface noise. 
Numerous tests have been made which indicated that for lacquer 
records the vertical force should not exceed 20 grams. A maximum 
value of 30 grams is considered satisfactory for shellac records. 

(2) Mechanical Impedance. The vertical and lateral mechanical 
impedances presented by the pick-up at the stylus should be as low 
as possible since the work which is performed by the record is a 
function of these impedances. Low mechanical impedance is like- 
wise desirable to minimize the mechanical noise or chatter radiated 
directly from the pick-up and record. 

(3) Free Resonance of Pick- Up. Experimental evidence indicates 
that it is desirable to keep the free resonance of the pick-up at as 
high a frequency as possible to minimize the effect of ticks and 
other record-groove irregularities. 

(4) Relationship between Stylus Displacement and Audio Output. 
If distortion is to be minimized it is essential that the pick-up 
and associated circuits provide a linear relationship between audio 
voltage output and stylus displacement. The necessity for mini- 
mizing distortion increases as the frequency range of a sound-re- 
producing system is extended. 

(5) Frequency Response Characteristic. A phonograph pick-up 
suitable for a high-fidelity system should provide a frequency response 
throughout the useful audio-frequency range which is proportional 
to either the amplitude or the velocity of the modulation in the 
record groove, 

(6) Sensitivity. The sensitivity of the pick-up should be such 
that the amplification required between the pick-up and loud speaker 
is not so great as to introduce serious microphonic difficulties. 

(B) FREQUENCY-MODULATION RECORD-REPRODUCING SYSTEM 

A review of the foregoing requirements led to a consideration of 
several types of record-reproducing systems. The possibility of 



224 



G. L. BEERS AND C. M. SINNETT 



[J. S. M. P. E. 



producing a frequency-modulated radio signal by means of a special 
pick-up was investigated. It was found that with a simple pick-up 
a frequency-modulated signal could be produced which had sufficient 
frequency deviation to provide a relatively high audio-frequency 
voltage output, when applied to a frequency discriminator and 
rectifier combination. Either the inductive or the capacitive 
reactance of a resonant circuit can be varied to produce a desired 
frequency shift. From the standpoint of a phonograph pick-up 
the control of frequency through a variation in capacity seemed to 
offer the greater advantage. 

(1) P.M. Pick-Up. Fig. 1 shows in outline form the general 
construction of an experimental frequency modulation pick-up. 
A metal frame or mounting block is provided as a support for an 

STEEL WRE ANCHORED IN BLOCK. 

MOUNTING BLOCK 



INSULATED METAL' 

STYLUS 




-.00)5" RIBBON 

STEEL WIRE ATTACHED 
TO RIBBON 



FIG. 1. Experimental frequency modulation pick-up. 



insulated plate which is the high-potential side of the pick-up. To 
this mounting block is also attached a thin metal ribbon. The ribbon, 
which is mounted in a plane parallel to the insulated plate and spaced 
from it by a small air-gap, is placed under tension in order to in- 
crease the natural resonance frequency of the system. The stylus- 
supporting wire is anchored to the mounting block at its upper end. 
It is attached to the ribbon at approximately the mid-point of its 
length and its free end is bent in a plane essentially parallel to the 
record groove. The sapphire which is used as a stylus is attached 
to the end of the wire. The portion of the wire between the ribbon 
and the sapphire provides sufficient vertical compliance to minimize 
mechanical noise and to reduce distortion due to pinch-effect. From 
the figure it is apparent that displacement of the stylus laterally 
results in a change in the position of the ribbon with respect to the 
fixed plate and thus produces a change in capacity. The overall 



I ; ' 

April, 1943] RECORD-REPRODUCING SYSTEMS 225 

length of the mounting block shown in Fig. 1 is approximately one- 
half inch. The normal spacing between the fixed plate and the 
ribbon is approximately 0.004 inch. 

From a purely theoretical standpoint it is essential that in a 
frequency modulation pick-up the change in capacity with dis- 
placement of the stylus be such as to produce a linear relationship 
between frequency change and motion of the stylus. In other words, 
the variable capacitor formed by the elements of the pick-up should, 
in radio terminology, be of the straight-line frequency type. From 
a practical standpoint the distortion introduced by a pick-up con- 
structed along the lines indicated in Fig. 1, when used with circuits 
to be described later, is sufficiently low as to be substantially neg- 
ligible. 

(2) Circuit Considerations. The essential circuit considerations 
which are involved in the design of a frequency-modulation record 
reproducing system may be stated as follows : 

(1) The carrier frequency to be employed. 

(2} A suitable oscillator circuit for use with the pick-up. 

(5) The type of frequency discriminator-rectifier combination to employ. 

A study of the question of the operating frequency to use in a 
frequency modulation phonograph system leads to the conclusion 
that carrier frequencies as low as those used in the intermediate- 
frequency amplifiers of radio receivers and as high as those employed 
for frequency modulation broadcasting will give satisfactory results. 
If the phonograph is to be used in combination with a radio receiver 
there may be some advantage in using a carrier frequency which 
permits the use of one or more of the intermediate-frequency amplifier 
circuits as a frequency-discriminating network for converting the 
frequency-modulated signal into amplitude modulation prior to 
detection. However, if the phonograph is designed as a separate 
device it may be desirable to use a frequency in the neighborhood 
of 30 megacycles, particularly in case some frequency in this region 
is assigned by the F.C.C. for diathermy machines. If a carrier 
frequency is used in a band thus allocated by the F.C.C. no special 
shielding would be required to prevent interference with other radio 
services. The signal level provided at the discriminator by the 
frequency-modulated oscillator can readily be made quite high, so 
there is no likelihood of diathermy machines or other electrical 
equipment causing interference with the phonograph. 



226 



G. L. BEERS AND C. M. SINNETT 



[J. S. M. P. E 



Since the oscillator and frequency discriminator-rectifier circuits 
are to a considerable extent interdependent, they will be discussed 
together. Fig. 2 is a schematic diagram of circuits which have 
given very satisfactory results. The circuit problem in connection 
with the oscillator is to provide an arrangement which will have 
sufficient frequency stability from the standpoint of line-voltage 
variations, temperature changes, etc., and at the same time enable 
the pick-up capacity variations to produce the desired frequency 
change. 

From the standpoint of obtaining the maximum frequency change 
for a given variation in capacity at the pick-up, it is desirable that 
the pick-up be connected directly across the oscillator tuned circuit 




FIG. 2. Oscillator and frequency discriminator-rectifier circuit. 

This can, of course, be accomplished by mounting the oscillator 
tube and associated circuit elements at the pick-up end of the tone 
arm. 

This arrangement has not been found to be particularly desirable 
because the tone arm is made unduly large and the heat from the 
oscillator tube causes the end of the tone arm, which is handled by 
the user, to become uncomfortably hot. The same result, however, 
can be accomplished by mounting the oscillator tube on the main 
instrument chassis and connecting it to the pick-up through a resonant 
transmission line, which is used as the oscillator tuned circuit. It 
has been found that by connecting the pick-up previously described 
through a relatively low-capacity line to a conventional oscillator 
circuit as shown in the diagram a sufficient frequency shift is obtained 
to give the desired audio-frequency output. In this case the trans- 



April, 1943] RECORD-REPRODUCING SYSTEMS 227 

mission line is treated as a lumped capacity. The line is included as 
an integral part of the tone arm. 

It will be noted that the oscillator tube employed is of the 5.47 
type. This tube permits the use of electronic coupling between the 
oscillator and discriminator circuits. The oscillator frequency is 
adjustable by means of an iron core which is associated with the 
inductance LI shown in the diagram. 

A simple resonant circuit is utilized as the means for converting 
the oscillator frequency variations into changes in the amplitude 
of the signal applied to the diode portion of the 6R7 tube. A pow- 
dered-iron core associated with inductance Lz is used to tune this 
circuit so that the mean oscillator frequency falls at approximately 
the 70 per cent response point on one side of the selectivity character- 
istic. The rectification of the r-f signal by the diode develops an 
audio-frequency potential across the resistor R&. This audio- 
frequency potential is then amplified by the triode section of the 6R7. 
The output voltage which appears across resistor R s in the plate 
circuit of the 6R7 is applied to a suitable audio-frequency amplifier 
and loud speaker. 

The audio-frequency output of the circuit shown in Fig. 2 is a 
function of: 

(1) The oscillator voltage applied to the discriminator. 

(2} The frequency variations in this voltage which are produced by the 
pick-up. 

(,?) The slope of the discriminator network. 

(4) The audio voltage gain obtained from the 6R7. 

An experimental pick-up employed in the circuit shown in Fig. 2 
has given an rms potential of 6 to 8 volts across resistor R 8 when 
reproducing a 400-cycle record cut at a groove amplitude of 0.001 
inch. 

(C) PERFORMANCE CHARACTERISTICS 

In the course of development of the frequency modulation pick- 
up system equations were derived for use in calculating the per- 
formance characteristics. Derivations of these equations will be 
found in the Appendixes. Through the use of these equations the 
following characteristics were calculated : 

(a) Lateral mechanical impedance. 

(&) Lateral force acting upon stylus. 

(c) Response characteristic of pick-up and tone arm. 



228 



G. L. BEERS AND C. M. SINNETT 



[J. s. M. P. E. 



(d) Tracking weight required to overcome vertical force due to lateral velocity . 

(e) Tracking weights and relative outputs to be obtained with different radius 
styli. 

For purposes of comparison measurements were made on an experi- 
mental pick-up to determine the last three of these characteristics. 

(1) Calculated Characteristics. (a) Lateral Mechanical Impe- 
dance: If sine-wave motion of the stylus on the record (perfect 
tracking) is assumed and the tone arm is of rigid construction then 



iy- yQJ>QJ>-QP-' I JU&a&b-ij] 1 3 - 1 

- 



FIG. 3. Equivalent electrical circuit for sine-wave stylus motion. 

L2 




FIG. 4. Equivalent electrical circuit for high frequencies. 




FIG. 5. Equivalent circuit for low frequencies. 

the equivalent electrical diagram shown in Fig. 3 may be set up. 
Since at high frequencies mass Ls (tone arm) is thousands of times 
higher than either the stylus or its supporting wire the equivalent 
diagram shown in Fig. 4 can be used. In this case the lateral im- 
pedance Z Ll becomes 



- 

L 



/jWMi 

l W 



+ G) 



Analyzing the above equation, it will be found that the lateral 
impedance Z Ll becomes infinite at/ = O,/ = oo and when/ = f ct where 



April, 1943] 



RECORD-REPRODUCING SYSTEMS 



229 



LATERAL MECHANICAL IMPEDANCE 
OF IB KC. PICKUP AND 2O~ TONE ARM 



ZERO IMPEDANCE OH 48OO ~ AND I700O 
NFINITE IMPEDANCE 20~ , ISOOO ~ AND 




FIG. 6. Calculated impedance of pick-up and tone-arm system. 

f e is the frequency at which the pick-up moving system resonates 
when the stylus is locked in the groove and may be expressed as 

1 



LATERAL FORCE ACTING UPON STYLUS 
OF 15 KC. PICKUP WITH 20 ~ TONE ARM 



SINE WAVE INPUT. 001" AMPLITUDE AT 500~AND 
BELOW ASSUMED. CONSTANT VELOCITY ABOVE 5*0* 



10OO 20OO BOOO tOOOC 




FIG. 7. 



Lateral force acting upon stylus due to record-groove modulation. 



230 



G. L. BEERS AND C. M. SINNETT 



[J. S. M. P. E. 



At low frequencies, we may again simplify by disregarding the 
stylus mass LI and the pick-up moving system mass L*. Fig. 5 
shows the equivalent diagram for low frequencies. 
In this case the lateral impedance Z L2 becomes 



Analyzing this equation it is found that Z L2 becomes infinite at 
f s the tone-arm swinging resonance where 




RESPONSE. 15 K.C. PICKUP WITH ZO ~ TONE. ARM 
CALCULATED FROM EQUIVALENT CIRCUIT 
D1A.3RAM AND ASSUMING A RECORD WITH 
CONSTANT VELOCITY ABOVE 5OO CYCLES. 



3O 50 10O 2 O 



s 



20000 5OOOO lOO OOO 



FIG. 8. Calculated response characteristic. 

Fig. 6 shows the calculated impedance of the pick-up and tone-arm 
system based on a pick-up locked resonance of 15 kc and a tone-arm 
swinging resonance of 20-cycles. 

The three points of zero impedance will be noted at / = 0, / = 
4800-cycles and/ = 17,000 cycles. Two points of infinite impedance 
occur as shown at/ = 20-cycles and/ = 15,000 cycles. 

(b) Lateral Force Acting upon Stylus: Using the calculated 
values of the effective mechanical impedance of the pick-up and 
tone-arm system jt is possible to calculate the lateral force acting 
upon the stylus due to record-groove modulation. For these cal- 
culations a groove-modulation of 0.001 inch amplitude up to 500- 



April, 1943] 



RECORD-REPRODUCING SYSTEMS 



231 



cycles and a constant groove-velocity above that frequency are 
assumed. Fig. 7 shows the curve obtained on the basis of these as- 
sumptions. It will be noted that the lateral force exerted on the 
stylus reaches a theoretically infinite value at 20-cycles and at 15,000- 
cycles, the resonance frequencies of the tone-arm and pick-up. 

(c) Response Characteristic of Pick- Up and Tone Arm: Making 
use of the equivalent diagrams in Figs. 4 and 5 the overall response 
characteristic of the system can be calculated. From these figures 
it can be seen that current i 3 represents the velocity of the ribbon 
with respect to the insulated plate and current i\ represents the ve- 
locity of the stylus. The ratio of ^ to i\ will provide the response 




iliiiriiimii 
0.0025 IN. 



FIG. 9. Stylus seated in record groove. 



characteristic of the pick-up with respect to frequency. For high- 
frequencies this can be calculated from the following formula 




For low frequencies, the response characteristic may be obtained 
from 



It will be noted that two peaks in response occur, one at tone-arm 
resonance and one at the high-frequency resonance of the pick-up 
moving system. Fig. 8 shows the response characteristic as cal- 
culated from the above equations. 



232 



G. L. BEERS AND C. M. SINNETT 



[J. S. M. P. E. 



(d) Tracking Weight Required to Overcome Vertical Force Due to 
Lateral Velocity: For proper tracking the stylus must have sufficient 
vertical force exerted upon it to overcome the vertical component 
of force due to the lateral velocity of the modulated record groove. 
Calculations have been made which show the vertical forces exerted 
upon styli of various radii when seated in a standard groove having 







































5 
































t 










































<0 
Ul 


















/ 
















-6- 


DEGRE 


















r 






























/ 




D AND <X 
DETER Wl 1 N E D GRAPH 1 C ALLY 




















/ 


































/ 




















-A. 


40 










/ 


/ 


/ 






^S 


\ 
























/ 


/ 












X 






















,'/ 
















X 


W 


















I 
























_2 


*>o 










^ 


'TH 
AL 

A.N 


iCRE 

,- T?; 

3 S- 


:TIC 

kDM 

rvL 


ALLY fi 
BELOW 
JS WERE 


3ES 
2.3 

PET! 


TO ' 
M1U 
FEC 


ZERO FO 
\F SROC 
TLV RG 


R v E 

D. 
















V 

i 




_\ 


1O 










1 
































/ 

_/ 


























O 


o 






-^ 


' 




























1 


J 


1 




\ 


ST 


CL.U, 


5 R> 


\DIU 


S,R 


S 
IN MIL. 


1 

s. 


3 




r 


& 



FIG. 10. Variation of d and a with stylus radius. 



an 88-degree included angle, a 0.0023-inch radius cutting stylus and 
a groove width at the top of 0.0069 inch. In addition to the vertical 
forces, consideration has also been given to the variations to be 
expected in pinch-effect with different sizes of reproducing styli. 

Fig. 9 illustrates a stylus seated in a record groove of the above 
dimensions. Two important factors which change the diameter 
of the stylus are: the tracking diameter (d) and the wedging-angle 
(a). Tracking diameter d has a direct bearing upon both pinch- 
eflfect and the high-frequency response and should be kept as small 



April, 1943] 



RECORD-REPRODUCING SYSTEMS 



233 



as possible. On the other hand, the wedging-angle a, which deter- 
mines the tendency of the stylus to climb the groove wall should be 
made as large as possible for a specified groove. From this it is 
obvious that a compromise must be made. Fig. 10 shows the varia- 



-6 



a 



zo 



-18 -9 



16 -8 



-7 



12 



10 -S 



8--4 



-3 



4--2 



2-1 



EFFECT OF STYLUS RADIUS UP'ON 



-\ I h 

TRACKING WEIGHT 



COT 0< 

FACTOR EFFECTING VERTICAL 
DUE TO LATERAL VELOCITY 



A 



\ 



345 

OF STYLES - MIL^ 



3 TAN 0< FACTOR 
EFFECTING 
VVINCH EFFECT 






FIG. 11. Effect of stylus radius upon tracking weight. 



tions in d and a with stylus radius, and from observation it can be 
seen that the stylus radius should not be less than 0.0025 inch or 
greater than 0.0042 inch. Furthermore, since the curve for angle 
a is flat from a stylus radius of 0.0025 inch to 0.0042 inch and the 
curve for diameter d is rising rapidly over this range it appears 
desirable, when record groove variations are considered, to use a 
stylus radius of about 0.003 inch. The importance of the tracking- 



234 



G. L. BEERS AND C. M. SINNETT 



\J. S. M. P. E. 



diameter d and the wedging-angle a is further emphasized by the 
curves in Fig. 11. This figure shows, in curve form, the two factors 
cot a and d tan a which have a direct bearing upon the vertical force 
due to lateral velocity and pinch effect, respectively. It will be 
observed that the curve for cot a approaches infinity for a stylus 
smaller than 0.0023 inch radius, decreases rapidly to about 0.0025 
inch radius and then remains essentially flat to 0.0042 inch. At 
the same time, however, d tan a, the factor governing pinch-effect, 
increases rapidly from a 0.0023-inch radius to a 0.0042-inch radius 
and then decreases. Observation of these two curves provides a 
further confirmation that a stylus radius of 0.003 inch is the best 
compromise from the standpoint of overall performance. 



\ 






TRACKING WEIGt 

CAl_< 
VAI 
15 K 


T REQUIRED TO OVER CO 
LATERAL, YEI 

-ULATED FOR STAND* 
IIOUS SIZES OF STYL 


ME VER 
LOCITY 

RD an 
us . u 

ONE AR 


TIC AL FORCE DUE TO 
30VE AND 

HTM 

M. 
















^ 


































\ 
























\ 






































A> AMPLITUDE OF RECORDIN6 




k 




S 




































5 






\ 


s 
































2 U . LATERAL IW1PEDANCE 


A 
\ 


y 








s 































































































































V 






























\ 














































oJ 




r 


- 


s 


F7I 


5 






= ^ 


s 
































































5 


S 


fc 
































































s^ 


^ 
































































^ 


^ 










/ 


t 






















































^ 


L 


Hi 


^ 








10 60 70 


100 20O 5OO 


1000 WOO 60 


00 10000 



FIG. 12. Calculated tracking weights for styli of different radii. 

In the above equations and those which follow such factors as the 
elasticity of record materials and the effective damping of the me- 
chanical system are not included. For this reason the calculated 
performance characteristics do not provide all the information that 
might be desired but they do give a general indication of the per- 
formance which can be expected. Expressed mathematically, the 
conditions for tracking a laterally cut record exist when 

Ev = ZLIL cot a 

where EV = minimum vertical force acting on the stylus which will insure proper 

tracking. 

*ZL = impedance of stylus and pick-up moving system in a lateral direction. 
IL = velocity of recording. 
a angle at which stylus would ride up groove wall. 



April, 1943] 



RECORD-REPRODUCING SYSTEMS 



235 



Utilizing the above equation and the previously determined values 
for the lateral impedance and the curve for angle a, it is possible to 
calculate the tracking- weight required to overcome the vertical force 
due to lateral velocity as the stylus radius is varied. Fig. 12 il- 
lustrates in curve form the calculated tracking-weights for stylus 
radii of 0.0023 inch, 0.003 inch, 0.004 inch, and 0.005 inch. It will 
be noted that a stylus radius of 0.003 inch to 0.004 inch required the 
least tracking- weight. 

(e) Tracking-Weights Required and Relative High- Frequency Out- 
puts to Be Obtained with Different Radius Styli: As the stylus radius 



















































Irt 






in 


-14 
-16 
-18 
-20 
-22 
-14 
-26 








































-i 

-z 

i 








. 


f 

















































*S 


->> 


* 


RA>C 


<INC 


UOSS FOR WAVE I.CNQ 

OF 5.3 Kill-. AT 7000 


rH 

CYCLES 






\ 


















^ 


N 
























j 






















\ 




















i 


* 


\- 
























\ 






















































? 


V 


8 








































z 


1 


Ul 

> 










































$ 


1 


4 




5 


-32 

-34 








































h 




a 










































1 










^ 


^n ,^ 










- 


TR 


POKING WEIGHT REQUIRED 
AT 7000 CYCLES. 




Q 














! 


< 


i , 


< 


. 


i 


> 




















1 












MIL.S ST> 

1 1 


LU: 


RADIUS 

1 1 ! 



















FIG. 13. Tracking loss at 7000 cps for styli of various radii. 

is increased, it is apparent that for a given groove velocity the out- 
put to be obtained at high frequencies will decrease. Calculations 
have been made of the expected loss at high frequencies, and Fig. 13 
shows the curve for this tracking loss at 7000 cycles for styli from 
0.0015 inch radius to 0.005 inch radius. It will again be noted that 
a stylus radius of 0.003 inch is indicated. 

(2) Measured Characteristics (a) Response Characteristics of 
Pick- Up and Tone Arm: Fig. 14, curve A shows the overall response 
characteristic of the pick-up, tone arm, and discriminator as ob- 
tained from a frequency record having a 500-cycle crossover point 
between constant amplitude and constant velocity. The rounded 
portion of this curve at the crossover frequency is due to the limita- 
tions imposed by the electrical network used to provide the recording 



236 



G. L. BEERS AND C. M. SINNETT 



[J. S. M. P. E. 



characteristic. For the purpose of comparison the calculated re- 
sponse characteristic previously shown in Fig. 8 is included in this 
figure as curve B. 

(b) Tracking-Weight Required to Overcome Vertical Force Due to 



FREQUENCY RESPONSE OF F.M. PICKUP. (MEAS.) 



(A) 



FIG. 14. Frequency response of F.M. pick-up. 







TRACKING WE 


ISHT REQUIRED TO OVERCOME VERT 
LATERAL VELOCITY 

UCUUATED FOR STANDARD GROOVE 


CAL FORCE. DUE TO 

. AND 
ANO 














Cl 

.0 














5 




2O CYCLE TONE ARM. 
































v=2 


TT AFZ L COT ot 
E.- A- AMPLITUDE OF RECORDINO 
F- FREQUENCY 
ZL LATERAL IMPEDANCE 




\ 


























\ 








MEASURED CUR 


VE 








\ 




\ 
















































\ 










































\ 


















































X 


,^- 













= = 


- 























- / 




























~ 


""> 


X 














r 






























(AK 




\ 


' 




-- 


- *" 






































(B) 


3 










, ' 








































\ 


^ ^ 


S 





500 1000 



FIG. 15. Measured and calculated minimum weights for satisfactory tracking 
with experimental pick-up. 



Lateral Velocity. A curve of the measured minimum weight required 
for satisfactory tracking with an experimental pick-up is shown in 
Fig. 15 as curve A. Curve B in this figure gives the calculated 
values for the same radius of stylus. The discrepancy between the 
curves at the higher frequencies is due to the fact that such factors 



April, 1943] 



RECORD-REPRODUCING SYSTEMS 



237 



as pinch effect, elasticity of the record material, and the Q of the 
mechanical system were not included in the calculations. 



























































-14 
-16 
-18 














































RELATIVE OUTPUT (lOOO ~ odb.) 








^ 
































TRACKING WEIGHT REQUIRE 


20 














">. 


^> 


^ 




c 

^-^ 


RAC 

)F 5 


KIN 
3 W 


G \_ 
!_. 


OSS 

CCA 


FOR 
I_CU 


WA> 
UAT 


E U 
ED> 


EM& 


CM 


iS 










OUTPUT AT ,>?*<> 
70OO ~ C MEASURED)^ 






16 




-22- 






















S 


v 
















'4 


























\ 
















IZ 












































10 












\ 
































5 












^ 


s. 










^ 


TRACKING WEIGHT REQUIRED AT 
7000 ~ ( MCASUR ED ) 


6 




-32 










^s 






































4 












































2 














^ 


^_ 










^ 


TRACKING WEIGHT 
7000 ~ CCAI-CO 


RC^UIRCO 
t-ATED) 


AT 

































1 














































> *\ 


LS 


STf 


uus 


KA 


3IUI 


t 







FIG. 16. 



Correlation between calculated and measured loss in response with 
increase of stylus radius. 

























SdlAW 

1 










y 


\0 
























/ 







O 










12 


to 


x 


/ 







i_ 










y 










Ul 
Of. 










Xuo 










5 








s 


X 














8 






S 




t< 


>0 










y 

o 














































.002 


.01 


)1 




1 


.oc 


>1 


,0( 


)2 








DISJ 


'LAC 


EMENT ( 

1 


>FS' 


rvLv 


JS 





FIG. 17. Relation between diode current and stylus displacement. 

(c) Tracking-Weights Required and Relative High- Frequency Out- 
puts to Be Obtained with Different Radius Styli: Fig. 16 shows the 
correlation between calculated and measured loss in response at 



238 



G. L. BEERS AND C. M. SINNETT 



. [J. S. M. P. E. 



7000 cycles as the stylus radius is increased. Also shown in the same 
figure are calculated and measured curves of the tracking-weight 
required for different styli at 7000 cycles. It will be noted that while 
the actual weights required are somewhat higher than the calculated 
values, because the factors previously mentioned were not included 
in the calculations, the curve shapes are similar indicating that the 
choice of a 0.003-inch stylus is a desirable compromise. 

(d) Change in Diode-Current with Stylus Displacement: Fig. 17 
shows the overall linearity existing between current in the diode 
resistor and displacement of the stylus. This curve shows the com- 
bined effect on linearity of the following factors : 



5000 10 000 



FIG. 18. Tracking weight required for P.M. pick-up and three other types of 

phonograph pick-ups. 

(1) Change in the capacity of the pick-up with displacement of the stylus. 

(2) Change in frequency of the oscillator with change in capacity of the 
pick-up. 

(5) Change in output of the frequency discriminator-rectifier combination 
with change in frequency. 

The departure from linearity of this curve represents a distortion of 
approximately 2 per cent second harmonic and 0.1 per cent third 
harmonic. The change in frequency which corresponds to the 
0.00 15-inch displacement of the stylus is =*= 15,000 cycles. 

(e) Comparison of Tracking-Weights Required for Various Pick- 
Ups: Fig. 18 shows the tracking- weight required for a frequency 
modulation pick-up as compared with three other types of phono- 
graph pick-ups. Curve A is a conventional crystal pick-up having 
a normal tracking- weight of 70 grams. Curve B is a transcription- 
type magnetic pick-up with a normal tracking weight of 45 grams. 
Curve C shows the tracking-weight characteristic of a recently de- 
veloped crystal pick-up which operates at a normal tracking-weight 



April, 1943] RECORD-REPRODUCING SYSTEMS 239 

of 28 grams, and curve D shows the tracking-weight characteristic 
:! of the frequency modulation pick-up normally operated with a 
tracking- weight of 18 grams. 

Conclusions. An experimental frequency-modulation record-re- 
producing system, of the type described, has been in use for some 
time. All the evidence to date indicates that the system is a practical 
one and is not adversely affected by changes in temperature, hu- 
midity, or line voltage. 

The experimental frequency modulation pick-up meets the re- 
quirements of a satisfactory pick-up to a degree which has not pre- 
viously been attained in a relatively inexpensive device. The general 
performance characteristics of a pick-up of this type can be cal- 
culated within reasonable limits. 

From the listener's standpoint, the experimental frequency 
modulation phonograph system which has been described makes it 
possible when using conventional shellac records to extend the 
frequency range of a record-reproducing system to 10,000 or 12,000 
cycles with surprising freedom from surface noise, mechanical 
noise, and distortion. Further reduction in surface noise can be 
obtained with shellac records if they are recorded with a high- 
frequency accentuation characteristic which is comparable to that 
used in transcriptions. Experimental records of this type have been 
made. The surface noise obtained from these records with the 
frequency-modulation reproducing system was reduced to the point 
where it was not objectional to the most critical listeners. 

Although the calculations and measurements which have been 
given are confined primarily to 78-rpm records, the same perform- 
ance advantages are retained in a frequency-modulation reproducing 
system designed for transcriptions. 

The writers wish to acknowledge the valuable assistance of Messrs. 
H. Belar and R. Snepvangers during the development of the fre- 
quency-modulation record-reproducing system. 






APPENDIX A 

Lateral Mechanical Impedance 

The equivalent diagram of the frequency modulation pick-up with a rigid tone- 
arm can be shown as indicated in Fig. 3, where 
LI = effective mass of needle point. 

L 2 = effective mass of ribbon and needle referred to point. 
L 3 = inertia of tone arm and pick-up referred to point. 
C 2 = compliance of needle between point and ribbon. 



240 G. L. BEERS AND C. M. SINNETT [j. s. M. P. E. 

Cz = compliance of ribbon and needle referred to point. 

ii = velocity of needle point. 

t's = velocity of ribbon with respect to support. 

Z L = mechanical impedance in lateral direction. 

In practice the mass of the tone arm is several hundred thousand times larger than 
that of either the point or needle. In view of this, further simplification is pos- 
sible and at high frequencies the equivalent diagram can be set up as shown in 
Fig. 4. 

For these frequencies the lateral mechanical impedance becomes: 



Z Ll = pLi + ^p^ ^f where p = jc 

pCz pC 3 

Ll 4. n 2/ 7 _i_ ^L 1 4. ^? , 1 

C- -p p J-/1-L/2 I ^i T^ x-t ~P o/^ 1 /^ 
2 C-^3 v^2 P Cx2l-^3 



COU2 



+ LjC, + I> 2 C 3 ) + 1 



- (Cz + G) 

From the above formula it can be seen that infinite impedance occurs when 
f =. oo ; f = or when 



At low frequencies Zi and L 2 become so small in value that they may be neg- 
lected and the equivalent diagram may be as shown in Fig. 5. 

The mechanical impedance of the pick-up and.Jone-arm system at low frequen- 
cies may be written as : 

X pL * 



- _ P(C 2 + C,) 



1 1 + P 2 L 3 (C 2 + C, 



C 8 ) 
Infinite impedance will then result when 



or when 

1 

= C s ) 



A.pril, 1943] RECORD-REPRODUCING SYSTEMS 241 

This point of infinite impedance occurs when the mass of the tone-arm resonates 
with the total compliance of the pick-up, and has been generally given the name 
of "swinging resonance." 

APPENDIX B 

Response Characteristics 

Assuming sine-wave motion of the pick-up point (perfect tracking) and refer- 
ring to the equivalent diagram, Fig. 4, it can be seen that the frequency response 
characteristic may be calculated from the ratio i 3 /ii, for high frequencies. 

Since i\ = iz + iz and also 



Substituting we obtain 
the ratio i 3 /i\ becomes 




Since the ratio of i*/i\ becomes infinite when 






c,c, 



the frequency of infinite response becomes 

1 



' C 2 + C 3 

By similar reasoning and making use of the equivalent diagram, Fig. 5, the low- 
frequency response at resonance may be calculated. In this case, 



ii (2 + C 8 ) (1 - o, 2 Z, 3 (C 2 + C,)) 

Here again the ratio of i 3 /i\ becomes infinite when 



_ / C 3 \ / 1____\ 

)) VC, + Cj VI - (27r/)lL 3 (C 2 + C 9 )J 






and the frequency of infinite response becomes 

1 

G) 



CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE 

ENGINEER 

The editors present for convenient reference a list of articles dealing with subjects 
cognate to motion picture engineering published in a number of selected journals. 
Photostatic copies may be obtained from the library of Congress, Washington, D. C., 
or from the New York Public Library, New York, N. Y. Micro copies of articles 
in magazines that are available may be obtained from the Bibliofilm Service, Depart- 
ment of Agriculture, Washington, D. C., at prevailing rates. 



American Cinematographer 

24 (Jan. 1943), No. 1 

Technical Progress in 1942 (pp. 6-7, 36-38) 

The Cameraman's Part in Television Production (pp. 
8-9, 30, 32, 34-35) E. ANHALT 

German Propaganda Movies in Two Wars (pp. 10-11, 
28) A. W. ROHDE, JR. 

Camerawork on a Convoy (pp. 12, 26, 28) H. PERRY 

Keeping Kodachrome Color Rendition Under Control 
(pp. 13, 30) A. STENSVOLD 

24 (Feb. 1943), No. 2 

Will There Be Cameraman- Directors in Television Pro- 
duction? (pp. 46-47, 78) E. ANHALT 

Forty-Eight Years of Home Movies (pp. 58-60, 73-74) W. STULL 

Pointers on Using Telephoto Lenses (pp. 61, 66, 68) J. SMITH 

Educational Screen 

21 (Dec. 1942), No. 10 

Motion Pictures Not for Theatres, Pt. 42 (pp. 386- 

387, 404) A. E. KROWS 

22 (Jan. 1943), No. 1 

Motion Pictures Not for Theatres, Pt. 43 (pp. 14-16) A. E. KROWS 
Edison Tried It, Too (pp. 17-18, 35) W. L. JAMISON 

Electronics 

16 (Jan. 1943), No. 1 
The Reduction of Record Noise by Pickup Design (pp. 



90-93, 198-199) 

Institute of Radio Engineers, Proceedings 

31 (Jan. 1943), No. 1 

Contemporary Problems in Television Sound (pp. 3-7) 
Automatic Frequency and Phase Control of Synchroni- 
zation in Television Receivers (pp. 7-15) 
Selected Problems in Architectural Acoustics (pp. 18-22) 

242 



A. D. DURT 



C. L. TOWNSEND 

K. R. WENDT AND 

G. L. FREDENDALL 
M. RETTINGER 



CURRENT LITERATURE 243 

Comparison of Voltage- and Current-Feedback Ampli- 
fiers (pp. 25-28) E. H. SCHULZ 

International Projectionist 

17 (Dec. 1942), No. 12 

Analyzing Amplifier Diagrams, Pt. Ill (pp. 7-9) L. CHADBOURNE 

Exhibit Teaches Science of Sound (p. 11) 

Kinematograph Weekly 

311 (Jan. 14, 1943), No. 1865 

Dufaycolor Is Branching Out in Numerous New Fields A. CORNWALL- 
(p. 24) CLYNE 



FIFTY-THIRD SEMI-ANNUAL MEETING 



OF THE 



SOCIETY OF MOTION PICTURE ENGINEERS 



HOTEL PENNSYLVANIA, NEW YORK, N. Y. 
MAY 4th-6th, INCLUSIVE 



Officers and Committees in Charge 

HERBERT GRIFFIN, President 

EMERY HUSE, Past- President 

LOREN L. RYDER, Executive Vice-President 

E. ALLAN WILLIFORD, Secretary 

D. E. HYNDMAN, Engineering V ice-President 

W. C. KUNZMANN, Convention Vice-President 

A. C. DOWNES, Editorial Vice-President 

ALFRED N. GOLDSMITH, Chairman, Local Arrangements Committee 

SYLVAN HARRIS, Chairman, Papers Committee 

JULIUS HABER, Chairman, Publicity Committee 

J. FRANK, JR., Chairman, Membership Committee 

H. F. HEIDEGGER, Chairman, Convention Projection Committee 

Reception and Local Arrangements 

ALFRED N. GOLDSMITH, Chairman 

M. BENNETT J. A. HAMMOND P. A. McGuiRE 

L. A. BONN M. HOBART J. A. NORLING 

M. R. BOYER C. F. HORSTMAN H. RUBIN 

J. C. BURNETT L. B. ISAAC E. I. SPONABLE 

A. S. DICKINSON E. W. KELLOGG J. H. SPRAY 

G. FRIEDL. JR J. H. KURLANDER R. O. STROCK 

W. E. GREEN J. A. MAURER H. E. WHITE 

Registration and Information 

E. R. GEIB F. HOHMEISTER 

J. FRANK, JR. P. K. SLEEMAN 

Hotel and Transportation 

O. F. NEU, Chairman 

M. W. PALMER J. A. SCHEICK 

P. D. RIES F. C. SCHMID 

C. Ross E. S. SEELEY 



J. W. DAVEE 

P. C. GOLDMARK 

R. F. MITCHELL 
244 



SEMI-ANNUAL MEETING 245 

S ' 

Publicity Committee 

JULIUS HABER, Chairman 

H. DESFOR C. R. KEITH P. A. McGuiRB 

C. R. DAILY S." HARRIS H. SHERMAN 

B 

g 

Luncheon and Banquet 

D. E. HYNDMAN, Chairman 

M. R. BOYER A. N. GOLDSMITH E. I. SPONABLE 

J. C. BURNETT O. F. NEU J. H. SPRAY 

A. S. DICKINSON M. W. PALMER E. A. WILLIFORD 

Projection Committee 

H. F. HEIDEGGER, Chairman 

M. BENNETT H. HOLLENDER A. L. RAVEN 

L. W. DAVEE J. J. HOPKINS P. D. RIBS 

J. K. ELDERKIN C. F. HORSTMAN J. E. ROBIN 

W. W. HENNESSY L. B. ISAAC H. RUBIN 

Officers and Members of New York Projectionists Local No. 306 

Hotel Reservations and Rates 

Hotel Rates. The Hotel Pennsylvania management extends to SMPE dele- 
gates and guests the following per diem rates, European plan : 

Room with bath, one person $3 . 85-$7 . 70 

Room with bath, two persons, double bed $5.50-$8.80 

Room with bath, two persons, twin beds $6.60-$9.90 

Parlor suites: living room, bedroom, and bath $10.00, 11.00, 13.00, 

and 18.00 

Reservations. Early in April Hotel room-reservation cards will be mailed to all 
the members of the Society. These cards should be returned to the Hotel as 
promptly as possible in order to be assured of accommodations. 

Due to the great influx of wartime visitors to New York it is often very diffi- 
cult to obtain accommodations, and for that reason reservations should be made 
well in advance of the meeting dates. It will not be possible to guarantee accom- 
modations if reservations are not made in advance. 

Registration. The registration headquarters for the Fifty-Third Semi-Annual 
Meeting will be on the 18th floor of the Hotel, at the entrance of the Salle Moderne, 
where the technical sessions will be held. All members and guests attending the 
meeting are expected to register and receive their identification cards and badges 
required for admission to all the sessions. 

Ladies' Activities. There will be no functioning Ladies' Committee or any 
specially planned Ladies' Program. However, a reception room will be provided 
for the ladies attending the Semi-Annual Meeting and they are cordially invited 
to participate in all the functions of the Meeting. 



246 



SEMI- ANNUAL MEETING 



[J. S. M. P. E. 



Technical Sessions 

The Papers Committee is assembling an attractive and interesting program of 
papers for the Meeting. Members and others who are contemplating the prepa- 
ration of papers should communicate immediately with the Chairman of the 
Papers Committee, at the office of the Society in the Hotel Pennsylvania, New 
York, N. Y. 

The assistance of the membership of the Society is earnestly sought by the 
Committee in the work of soliciting papers, and suggestions as to possible presen- 
tations and authors will be gratefully received. 



Fifty-Third Semi- Annual Banquet and Informal Get-Together Luncheon 

The usual Get-Together Luncheon for members, their families, and guests will 
be held in the Roof Garden of the Hotel on Tuesday, May 4th, at 12 : 30 P. M. 

The Fifty-Third Semi-Annual Banquet and Dance will be held in the Georgian 
Room of the Hotel on Wednesday, May 5th, at 8: 00 P. M. an evening of sociabil- 
ity and dancing. 



TENTATIVE PROGRAM 

Tuesday, May 4th 

9 : 00 a.m. Hotel Roof; Registration 

10:00 a.m. Salle Moderne; Business and Technical Session 
12: 30 p.m. Roof Garden; SMPE Get-Together Luncheon for members, their 
families, and guests. Addresses by eminent speakers, names to be 
announced later 
2 : 00 p.m. Salle Moderne; Technical Session 

The evening of this date will be left open 



Wednesday, May 5th 

9 : 30 a.m. Hotel Roof; Registration 

10:00 a.m. Salle Moderne; Technical Session 

1 2 : 30 p.m. Luncheon Period 

2 : 00 p.m. Salle Moderne; Technical Session 

8:00 p.m. Georgian Room; Fifty-Third Semi-Annual Banquet and Dance 



Thursday, May 6th 

9:30 a.m. Hotel Roof; Registration 

10:00 a.m. Salle Moderne; Technical Session 

12: 30 p.m. Luncheon period 

2 : 00 p.m. Salle Moderne; Technical Session 



April, 1943] 



SEMI-ANNUAL MEETING 



247 



Miscellaneous 

Motion Pictures. The identification cards issued at the time of registering will 
be honored at a number of de luxe motion picture theaters in the vicinity of the 
Hotel. Many entertainment attractions are available in New York to out-of- 
town delegates and guests, information concerning which may be obtained at the 
Hotel information desk or at the registration headquarters. 

Parking. Parking accommodations will be available to those motoring to the 
meeting at the Hotel garage, at the rate of $1.25 for 24 hours, and in the open lot 
at 75 cents for day parking. These rates include car pick-up and delivery at the 
door of the Hotel. 

Note: The 1943 Spring Meeting is subject to cancellation if later deemed ad- 
visable in the national interest. 

W. C. KUNZMANN 
Convention Vice- President 



IMPORTANT 

Hotel registration cards must be re- 
turned immediately. Otherwise the 
Hotel can not guarantee accommoda- 
tion, on account of the large influx of 
visitors to New York. 



OFFICERS AND GOVERNORS OF THE SOCIETY 




DONALD E. HYNDMAN LOREN L. RYDER 

Engineering Vice-President Executive Vice-f 'resident 



ARTHUR C. DOWNES 
Editorial Vice-P resident 




HERBERT GRIFFIN 

President 






ARTHUR S. DICKINSON 
Financial Vice-P resident 

248 



EMERY HUSE 
Past-President 



WILLIAM C. KUNZMANN 
Convention Vice-President 



OFFICERS AND GOVERNORS OF THE SOCIETY 



249 





E. ALLAN WILLIFORD 
Secretary 



M. R. BOYER 
Treasurer 





FRANK E. CARLSON 
Governor 



EDWARD M. HONAN 
Governor 



JOHN A. MAURER 
Governor 




WILLIAM A. MUELLER 
Governor 



JOSEPH H. SPRAY 
Governor 



HOLLIS W. MOYSE 
Governor 



250 OFFICERS AND GOVERNORS OF THE SOCIETY 





A. M. GUNDELFINGER 

Governor 



H. W. REMERSHIED 
Governor 





ALFRED N. GOLDSMITH 

Chairman, 
Atlantic Coast Section 



REEVE O. STROCK 
Governor 



CHARLES W. HANDLEY 

Chairman, 
Pacific Coast Section 



C. N. BATSEL 
M. W. PALMER 



ATLANTIC COAST SECTION 

ALFRED N. GOLDSMITH, Chairman 
R. O. STROCK, Past-Chairman 
M. R. BOYER, Sec.-Treas. 

E. I. SPONABLE 

P. C. GOLDMARK 



H. E. WHITE 

W. H. OFFENHAUSER 



J. R. WILKINSON 
J. K. HILLIARD 



PACIFIC COAST SECTION 

CHARLES W. HANDLEY, Chairman 
J. G. FRAYNE, Past-Chairman 
S. P. SOLOW, Sec.-Treas. 

H. W. MOYSE 

M. S. LESHING 



G. A. SAWYER 
W. V. WOLFE 



COMMITTEES OF THE SOCIETY 



(Correct to March 15th; additional appointments or changes may be made at any 
time during the year, as necessity or expediency may require.) 

Admissions 



M. R. BOYER 
H. D. BRADBURY 



(East Coast) 

A. S. DICKINSON, Chairman 
J. FRANK, JR. 
G. FRIEDL, JR. 



D. E. HYNDMAN 
H. RUBIN 



(West Coast) 
EMERY HUSE, Chairman 



C. W. HANDLE Y 
H. W. MOYSE 



W. A. MUELLER 
H. W. REMERSHIED 



J. I. CRABTREE 
A. N. GOLDSMITH 



F. T. BOWDITCH 
L. E. CLARK 



J. G. FRAYNE 
J. HABER 



A. S. DICKINSON 
T. FAULKNER 
G. K. GIROUX 



Board of Editors 

A. C. DOWNES, Chairman 

A. M. GUNDELFINGER 

A. C. HARDY 
E. W. KELLOGG 

Cinematography 

J. W. BOYLE, Chairman 

Color 

R. M. EVANS, Chairman 
J. B. ENGL 

Convention 

W. C. KUNZMANN, Chairman 
S. HARRIS 
H. F. HEIDEGGER 

Exchange Practice 

J. S. MACLEOD, Chairman 
G. K. HADDOW 
S. HARRIS 
L. B. ISAAC 
H. C. KAUFMAN 



C. R. KEITH 
C. R. SAWYER 



A. M. GUNDELFINGER 
A. C. HARDY 



O. F. NEU 
R. O. STROCK 



N. F. OAKLEY 

A. W. SCHWALBERG 
J. SlCHELMAN 

251 



252 



COMMITTEES OF THE SOCIETY 



LT. S. M. p. E. 



Fellow Membership 

EMERY HUSE, Chairman 

M. R. BOYER A. N. GOLDSMITH W. C. KUNZMANN 

A. S. DICKINSON H. GRIFFIN L. L. RYDER 

A. C. DOWNES C. W. HANDLEY E. A. WILLIFORD 

D. E. HYNDMAN 

Historical and Museum 

J. E. ABBOTT, Chairman 
O. B. DEPUE R. GRIFFITH T. RAMSAYE 

Honorary Membership 

E. A. WILLIFORD, Chairman 

Journal Award 

SYLVAN HARRIS, Chairman 
F. G. ALBIN J. A. MAURER 

J. G. FRAYNE C. R. KEITH 



Laboratory Practice 

H. E. WHITE, Chairman 
J. O. BAKER G. H. GIBSON 

A. C. BLANEY E. HUSE 

L. A. BONN T. M. INGMAN 

O. B. DEPUE C. L. LOOTENS 

J. A. BUBRAY A. J. MILLER 

J. G. FRAYNE R. F. MITCHELL 

H. W. MOYSE 

Membership and Subscription 

J. FRANK, JR., Chairman 

T. C. BARROWS S. HARRIS 

J. G. BRADLEY L. B. ISAAC 

K. BRENKERT W. C. KUNZMANN 

L. W. CHASE S. A. LUKES 

J. P. CORCORAN G. E. MATTHEWS 

E. R. GEIB W. A. MUELLER 

Non-Theatrical Equipment 

J. A. MAURER, Chairman 
J. G. BLACK J. A. HAMMOND 

F. E. CARLSON M. L. HOBART 
J. CLARKE R. C. HOLSLAG 
N. B. GREEN R. KINGSLAKE 
F. M. HALL D. F. LYMAN 

R. F. MITCHELL 



J. M. NICKOLAUS 

N. F. OAKLEY 

W. H. OFFENHAUSER 

W. A. SCHMIDT 

J. H. SPRAY 

J. R. WILKINSON 



H. B. SANTEE 
G. E. SAWYER 
W. L. THAYER 
C. R. WOOD 

E. A. WlLSCHKE 

W. V. WOLFE 



W. H. OFFENHAUSER 
L. T. SACHTLEBEN 
A. SHAPIRO 
M. G. TOWNSLEY 
A. G. ZIMMERMAN 



April, 1943] 



? F. T. BOWDITCH 
G. A. CHAMBERS 
F. L. EICH 
R. E. FARNHAM 



J. E. ABBOTT 
J. I. CRABTREE 
A. S. DICKINSON 



F. R. ABBOTT 
A. H. BOLT 



F. T. BOWDITCH 

G. L. DIMMICK 



COMMITTEES OF THE SOCIETY 

Papers 

S. HARRIS, Chairman 
C. R. DAILY, West Coast Chairman 
J. L. FORREST 

E. W. KELLOGG 
C. R. KEITH 

P. A. McGuiRE 
J. FRANK, JR. 

Preservation of Film 

J. G. BRADLEY, Chairman 
R. M. EVANS 
J. L. FORREST 

Process Photography 

WILLIAM THOMAS, Chairman 

F. M. FALGE 
C. S. HANDLEY 
W. C. HOCH 

Progress 

G. A. CHAMBERS, Chairman 
J. A. DUBRAY 
M. S. LESHING 



253 



G. E. MATTHEWS 
W. H. OFFENHAUSER 
S. P. SOLOW 
W. V. WOLFE 



C. L. GREGORY 
T. RAMSAYB 
V. B. SEASE 



G. LAUBE 

G. H. WORRALL 



G. E. MATTHEWS 
D. R. WHITE 



Progress Award 

J. I. CRABTREE, Chairman 



G. A. CHAMBERS 
P. A. McGuiRE 



Publicity 

J. HABER, Chairman 
C. R. DAILY 
G. GIROUX 



S. HARRIS 
H. DESFOR 



J. O. AALBERG 
L. A. AICHOLTZ 
M. C. BATSEL 
D. G. BELL 
D. BLUMBERG 
F. E. CAHILL 
C. FLANNAGAN 



Sound 

G. E. SAWYER, Chairman 
G. FRIEDL, JR. 
E. H. HAN SEN 
L. B. ISAAC 
J. P. LIVADARY 
J. A. MAURER 

R. McCULLOUGH 

B. F. MILLER 



W. C. MILLER 
K. F. MORGAN 
F. ROBERTS 
H. RUBIN 
S. SOLOW 
W. V. WOLFE 
E. C. ZRENNER 



254 



COMMITTEES OF THE SOCIETY 



tf. S. M. P. E. 



J. M. ANDREAS 
P. H. ARNOLD 
H. BARNETT 
C. N. BATSEL 
M. C. BATSEL 
F. T. BOWDITCH 
M. R. BOYER 
F. E. CARLSON 
T. H. CARPENTER 
E. K. CARVER 



Standards 

D. B. JOY, Chairman 

H. B. CUTHBERTSON 

L. W. DAVEE 
J. A. DUBRAY 
A. F. EDOUART 
J. L. FORREST 
A. N. GOLDSMITH 
H. GRIFFIN 
A. C. HARDY 
C. R. KEITH 
P. J. LARSEN 



R. LlNDERMAN 

C. L. LOOTENS 
J. A. MAURER 
G. S. MITCHELL 
W. H. OFFENHAUSER 
G. F. RACKETT 
W. B. RAYTON 
H. RUBIN 
O. SANDVIK 
H. E. WHITE 



J. W. BOYLE 
R. E. FARNHAM 



Studio Lighting 

R. LINDERMAN, Chairman 
K. FREUND 

C. W. HANDLEY 

D. B. JOY 



A. RODGERS 

K. STRAUSS 



H. BAMFORD 
R. L. CAMPBELL 
E. D. COOK 
C. E. DEAN 
J. B. ENGL 
A. N. GOLDSMITH 



Television 

P. C. GOLDMARK, Chairman 
T. T. GOLDSMITH 
H. GRIFFIN 
A. C. JENSEN 
P. J. LARSEN 
H. B. LUBCKE 
I. G. MALOFF 



J. A. MAURER 
P. MERTZ 
A. MURPHY 
O. SANDVIK 
R. E. SHELBY 
H. E. WHITE 



H. ANDERSON 
T. C. BARROWS 
H. D. BEHR 
M. BENNETT 
K. BRENKERT 
F. E. CAHILL, JR. 
C. C. DASH 
A. S. DICKINSON 
J. K. ELDERKIN 
J. FRANK, JR. 



Theater Engineering 

ALFRED N, GOLDSMITH, Chairman 

Projection Practice, Sub- Committee 
C. F. HORSTMAN, Sub-Chairman 
R. R. FRENCH 
E. R. GEIB 
M. GESSIN 
A. GOODMAN 
H. GRIFFIN 
S. HARRIS 
J. J. HOPKINS 
L. B. ISAAC 
I. JACOBSEN 



J. H. LlTTENBERG 

E. R. MORIN 
J. R. PRATER 

F. H. RICHARDSON 
H. RUBIN 

J. J. SEFING 
R. O. WALKER 
V. A. WELMAN 
H. E. WHITE 
A. T. WILLIAMS 



April, 1943] 



COMMITTEES OF THE SOCIETY 



255 



F. W. ALEXA 
J. R. CLARK 
E. EBERSON 



H. BARNETT 
E. R. GEIB 
S. HARRIS 



Theater Design Sub- Committee 
B. SCHLANGER, Sub- Chair man 
J. FRANK, JR. 
M. M. HARE 
S. HARRIS 
C. F. HORSTMAN 

Screen Brightness Sub-Committte 
F. E. CARLSON, Sub- Chair man 

W. F. LITTLE 

W. B. RAYTON 



E. R. MORIN 
A. L. RAVEN 
J. J. SEEING 



C. TUTTLE 

H. E. WHITE 
A. T. WILLIAMS 



Sub- Committee on Civilian Defense in Theaters 

H. ANDERSON, Sub- Chair man 

F. E. CARLSON SYLVAN HARRIS E. R. MORIN 

E. W. FOWLER C. F. HORSTMAN B. SCHLANGER 

J. FRANK, JR. GILBERT TYLER 

SMPE REPRESENTATIVES TO OTHER ORGANIZATIONS 



American Documentation Institute 

Sectional Committee on Motion Pictures, ASA 



Sectional Committee on Photography, ASA 
Inter-Society Color Council 



Sectional Committee on Standardization of Letter Symbols 
and Abbreviations for Science and Engineering, ASA 



J. E. ABBOTT 
A. N. GOLDSMITH 
E. A. WILLIFORD 

E. K. CARVER 
J. I. CRABTREE 
G. F. RACKETT 
J. A. BALL 

F. T. BOWDITCH 
J. G. CAPSTAFF 
L. A. JONES 



J. O. AALBERG 
P. H. ARNOLD 
M. C. BATSEL 
C. R. BROWN 
B. H. CARROLL 
E. K. CARVER 
KENNETH CLARK 
W. CLARK 
A. S. DICKINSON 
J. A. DUBRAY 



American Standards Association 
Sectional Committee on Motion Pictures (Z22) 

ALFRED N. GOLDSMITH, Chairman 

C. R. KEITH, Secretary 
F. EDOUART 

E. W. ELY 
R. E. FARNHAM 
H. GRIFFIN 
R. G. HOLSLAG 
L. A. JONES 

D. B. JOY 

* (E. A. WILLIFORD) 



G. A. MITCHELL 
* (J. RUTTENBERG) 



WM. KELLEY 
O. F. NEU 
N. F. OAKLEY 

* (M. R. BOYER) 
D. PALFREYMAN 
A. R. SMALL 

* (G. W. BOOTH) 
J. L. SPENCE 

H. G. TASKER 
G. H. WORRALL 



* Alternate. 



CONSTITUTION AND BY-LAWS 

OF THE 
SOCIETY OF MOTION PICTURE ENGINEERS* 

CONSTITUTION 
Article I 

Name 

The name of this association shall be SOCIETY OF MOTION PICTURE 
ENGINEERS. 

Article II 

Object 

Its objects shall be: Advancement in the theory and practice of motion pic- 
ture engineering and the allied arts and sciences, the standardization of the equip- 
ment, mechanisms, and practices employed therein, the maintenance of a high 
professional standing among its members, and the dissemination of scientific 
knowledge by publication. 

Article III 

Eligibility 

Any person of good character may be a member in any grade for which he is 
eligible. 

Article IV 

Officers 

The officers of the Society shall be a President, a Past-President, an Executive 
Vice-President, an Engineering Vice-President, an Editorial Vice-President, a 
Financial Vice-President, a Convention Vice-President, a Secretary, and a 
Treasurer. 

- The term of office of the President, the Past-President, the Executive Vice- 
President, the Engineering Vice-President, the Editorial Vice-President, the 
Financial Vice-President, and the Convention Vice-President shall be two years, 
and the Secretary and the Treasurer one year. Of the Engineering, Editorial, 
Financial, and Convention Vice-Presidents, two shall be elected alternately each 
year, or until their successors are chosen. The President shall not be immediately 
eligible to succeed himself in office. 

Article V 

Board of Governors 

The Board of Governors shall consist of the President, the Past-President, 
the five Vice-Presidents, the Secretary, the Treasurer, the Section Chairmen and 

* Corrected to March 15, 1943. 
256 



CONSTITUTION AND BY-LAWS 257 

1 

ten elected governors. Five of these governors shall be resident in the area operat- 
ing under Pacific and Mountain time, and five of the governors shall be resident 
in the area operating under Central and Eastern time. Two of the governors 
from the Pacific area and three of the governors from the Eastern area shall be 
elected in the odd-numbered years, and three of the governors in the Pacific area 
and two of the governors in the Eastern area shall be elected in the even-numbered 
years. The term of office of all elected governors shall be for a period of two 
years. 

Article VI 

Meetings 

There shall be an annual meeting, and such other meetings as stated in the 
By-Laws. 

Article VII 

Amendments 

This Constitution may be amended as follows : Amendments shall be approved 
by the Board of Governors, and shall be submitted for discussion at any regular 
members' meeting. The proposed amendment and complete discussion then 
shall be submitted to the entire Active, Fellow, and Honorary membership, 
together with letter ballot as soon as possible after the meeting. Two-thirds of 
the vote cast within sixty days after mailing shall be required to carry the amend- 
ment. 

BY-LAWS 
By-Law I 

Membership 

Sec. 1. The membership of the Society shall consist of Honorary members, 
Fellows, Active members, Associate members, Student members, and Sustaining 
members. 

An Honorary member is one who has performed eminent services in the ad- 
vancement of motion picture engineering or in the allied arts. An Honorary 
member shall be entitled to vote and to hold any office in the Society. 

A Fellow is one who shall not be less than thirty years of age and who shall 
comply with the requirements of either (a) or (6) for Active members and, in 
addition, shall by his proficiency and contributions have attained to an out- 
standing rank among engineers or executives of the motion picture industry. 
A Fellow shall be entitled to vote and to hold any office in the Society. 

An Active member is one who shall be not less than 25 years of age, and shall 
be: 

(a) A motion picture engineer by profession. He shall have been engaged in 
the practice of his profession for a period of at least three years, and shall have 
taken responsibility for the design, installation, or operation of systems or ap- 
paratus pertaining to the motion picture industry. 



258 CONSTITUTION AND BY-LAWS tf. s. M. P. E. 

(&) A person regularly employed in motion picture or closely allied work, 
who by his inventions or proficiency in motion picture science or as an executive 
of a motion picture enterprise of large scope, has attained to a recognized stand- 
ing in the motion picture industry. In case of such an executive, the applicant 
must be qualified to take full charge of the broader features of motion picture 
engineering involved in the work under his direction. 

(c) An Active member is privileged to vote and to hold any office in the So- 
ciety. 

An Associate member is one who shall be not less than 18 years of age, and shall 
be a person who is interested in or connected with the study of motion picture 
technical problems or the application of them. An Associate member is not privi- 
leged to vote, to hold office or to act as chairman of any committee, although he 
may serve upon any committee to which he may be appointed; and, when so 
appointed, shall be entitled to the full voting privileges of a committee member. 

(d) A student member is any person registered as a student, graduate or under- 
graduate, in a college, university, or educational institution, pursuing a course of 
studies in science or engineering that evidences interest in motion picture tech- 
nology. Membership in this grade shall not extend more than one year beyond 
the termination of the student status described above. A student member shall 
have the same privileges as Associate members of the Society. 

A Sustaining member is an individual, a firm, or corporation contributing 
substantially to the financial support of the Society. 

Sec. 2. All applications for membership or transfer, except for honorary or 
fellow membership, shall be made on blank forms provided for the purpose, and 
shall give a complete record of the applicant's education and experience. Honor- 
ary and Fellow membership may not be applied for. 

Sec. 3. (a) An Honorary membership may be granted upon recommendation 
of the Board of Governors when confirmed by a four-fifths majority vote of the 
Honorary members, Fellows, and Active members present at any regular meeting 
of the Society. An Honorary member shall be exempt from all dues. 

(6) Fellow membership may be granted upon recommendation of the Fellow 
Membership Award Committee, when confirmed by a three-fourths majority vote 
of the Board of Governors. 

(c) Applicants for Active Membership shall give as reference at least three 
members of Active or of higher grade in good standing. Applicants shall be elected 
to membership by the unanimous approval of the entire membership of the ap- 
propriate Admissions Committee. In the event of a single dissenting vote or 
failure of any member of the Admissions Committee to vote, the application shall 
be referred to the Board of Governors, in which case approval of at least three- 
fourths of the Board of Governors shall be required. 

(d) Applicants for Associate membership shall give as reference at least one 
member of higher grade in good standing. Applicants shall be elected to member- 
ship by approval of a majority of the appropriate Admissions Committee. 

() Applicants for student membership shall give as reference the head of the 
Department of the Institution he is attending; this faculty member not neces- 
sarily being a member of the Society. 



A 



April, 1943] CONSTITUTION AND BY-LAWS 259 

By-Law II 



Officers 

Sec. 1. An officer or governor shall be an Honorary, a Fellow, or Active mem- 
ber. 

Sec. 2. Vacancies in the Board of Governors shall be filled by the Board of 
Governors until the annual meeting of the Society. 

By-Law III 

Board of Governors 

Sec. 1. The Board of Governors shall transact the business of the Society 
between members' meetings, and shall meet at the call of the president, with the 
proviso that no meeting shall be called without at least seven (7) days' prior 
notice, stating the purpose of the meeting, to all members of the Board by letter or 
by telegram. 

Sec. 2. Nine members of the Board of Governors shall constitute a quorum 
at all meetings. 

Sec. 3. When voting by letter ballot, a majority affirmative vote of the total 
membership of the Board of Governors shall carry approval, except as otherwise 
provided. 

Sec. 4. The Board of Governors, when making nominations to office, and to 
the Board, shall endeavor to nominate persons, who in the aggregate are repre- 
sentative of the various branches or organizations of the motion picture industry, 
to the end that there shall be no substantial predominance upon the Board, as the 
result of its own action, of representatives of any one or more branches or organi- 
zations of the industry. 

By-Law IV 

Committees 

Sec. 1. All committees, except as otherwise specified, shall be appointed by the 
President. 

Sec. 2. All committees shall be appointed to act for the term served by the 
officer who shall appoint the committees, unless their appointment is sooner ter- 
minated by the appointing officer. 

Sec. 3. Chairmen of the committees shall not be eligible to serve in such ca- 
pacity for more than two consecutive terms. 

Sec. 4. Standing committees of the Society shall be as follows to be appointed 
as designated: 

(a) Appointed by the President and confirmed by the Board of Governors 
Progress Award Committee 
Journal Award Committee 
Honorary Membership Committee 
Fellow Membership Award Committee 
Admissions Committees 

(Atlantic and Mid-West Sections) 
(Pacific Coast Section) 
European Advisory Committee 



260 CONSTITUTION AND BY-LAWS [J. S. M. P. E. 

(b) Appointed by the Engineering Vice- President 

Sound Committee 
Standard Committee 
Studio Lighting Committee 
Color Committee 
Theater Engineering Committee 
Exchange Practice Committee 
Non-Theatrical Equipment Committee 
Television Committee 
Laboratory Practice Committee 
Committee on Cinematography 
Process Photography Committee 
Committee on Preservation of Film 

(c) Appointed by Editorial Vice- President 

Board of Editors 
Papers Committee 
Progress Committee 
Historical Committee 
Museum Committee 

(d) Appointed by Convention Vice-President 

Publicity Committee 

Convention Arrangements Committee 

Apparatus Exhibit Committee 

(e) Appointed by Financial Vice- President 

Membership and Subscription Committee 

Sec. 5. Two Admissions Committees, one for the Atlantic and Mid- West 
Sections, and one for the Pacific Coast Section, shall be appointed. The former 
committee shall consist of a chairman and six Fellow or Active members of the 
Society of which four shall be members of the Board of Governors. The latter 
committee shall consist of a Chairman and four Fellow or Active members of the 
Society including all officers or members of the Board of Governors of the Society 
residing in the Pacific Coast Section. 

By-Law V 

Meetings 

Sec. 1 . The location of each meeting of the Society shall be determined by the 
Board of Governors. 

Sec. 2. Only Honorary members, Fellows, and Active members shall be en- 
titled to vote. 

Sec. 3. A quorum of the Society shall consist in number of one-tenth of the 
total number of Honorary members, Fellows, and Active members as listed in 
the Society's records at the close of the last fiscal year. 

Sec. 4. The fall convention shall be the annual meeting. 

Sec. 5. Special meetings may be called by the president and upon the request 
of any three members of the Board of Governors not including the president. 

Sec. 6. All members of the Society in any grade shall have the privilege of dis- 
cussing technical material presented before the Society or its Sections. 



April, 1943] CONSTITUTION AND BY-LAWS 261 

By-Law VI 

Duties of Officers 

Sec. 1. The president shall preside at all business meetings of the Society and 
shall perform the duties pertaining to that office. As such he shall be the chief 
executive of the Society, to whom all other officers shall report. 

Sec. 2. In the absence of the president, the officer next in order as listed in 
Article 4 of the Constitution shall preside at meetings and perform the duties of 
the president. 

Sec. 3. The five vice-presidents shall perform the duties separately enumerated 
below for each office, or as defined by the president : 

(a) The executive vice-president shall represent the president in such geo- 
graphical areas of the United States as shall be determined by the Board of Gover- 
nors, and shall be responsible for the supervision of the general affairs of the 
Society in such areas, as directed by the president of the Society. 

(6) The engineering vice-president shall appoint all technical committees. 
He shall be responsible for the general initiation, supervision, and coordination of 
the work in and among these committees. He may act as chairman of any com- 
mittee or otherwise be a member ex-officio. 

(c) The editorial vice-president shall be responsible for the publication of the 
Society's JOURNAL and all other technical publications. He shall pass upon the 
suitability of the material for publication, and shall cause material suitable for 
publication to be solicited as may be needed. He shall appoint a papers com- 
mittee and an editorial committee. He may act as chairman of any committee 
or otherwise be a member ex-officio. 

( d) The financial vice-president shall be responsible for the financial operations 
of the Society, and shall conduct them in accordance with budgets approved by 
the Board of Governors. He shall study the costs of operation and the income 
possibilities to the end that the greatest service may be rendered to the members 
of the Society within the available funds. He shall submit proposed budgets to 
the Board. He shall appoint at his discretion a ways and means committee, a 
membership committee, a commercial advertising committee, and such other 
committees within the scope of his work as may be needed. He may act as chair- 
man of any of these committees or otherwise be a member ex-officio. 

(e) The convention vice-president shall be responsible for the national con- 
ventions of the society. He shall appoint a convention arrangements committee, 
an apparatus exhibit committee, and a publicity committee. He may act as 
chairman of any committee, or otherwise be a member ex-officio. 

Sec. 4. The secretary shall keep a record of all meetings; he shall conduct the 
correspondence relating to his office, and shall have the care and custody of 
records, and the seal of the Society. 

Sec. 5. The treasurer shall have charge of the funds of the Society and disburse 
them as and when authorized by the financial vice-president. He shall make 
an annual report, duly audited, to the Society, and a report at such other times 
as may be requested. He shall be bonded in an amount to be determined by the 
Board of Governors and his bond filed with the Secretary. 

Sec. 6. Each officer of the Society, upon the expiration of his term of office, 
shall transmit to his successor a memorandum outlining the duties and policies 
of his office. 



262 CONSTITUTION AND BY-LAWS [J. S. M. P. E. 

By-Law VII 

Elections 

Sec. 1. (a) All officers and five governors shall be elected to their respective 
offices by a majority of ballots cast by the Active, Fellow, and Honorary members 
in the following manner: 

Not less than three months prior to the annual fall convention, the Board of 
Governors shall nominate for each vacancy several suitable candidates. Nomi- 
nations shall first be presented by a Nominating Committee appointed by the 
President, consisting of nine members, including a chairman. The committee 
shall be made up of two Past-Presidents, three members of the Board of Governors 
not up for election, and four other Active, Fellow, or Honorary members, not 
currently officers or Governors of the Society. Nominations shall be made by 
three-quarters affirmative vote of the total Nominating Committee. Such nomi- 
nations shall be final unless any nominee is rejected by a three-quarters vote of 
the Board of Governors present and voting. 

The secretary shall then notify these candidates of their nomination. From 
the list of acceptances, not more than two names for each vacancy shall be se- 
lected by the Board of Governors and placed on a letter ballot. A blank space 
shall be provided on this letter ballot under each office, in which space the names 
of any Active, Fellow, or Honorary members other than those suggested by the 
Board of Governors may be voted for. The balloting shall then take place. 

The ballot shall be enclosed in a blank envelope which is enclosed in an outer 
envelope bearing the secretary's address and a space for the member's name and 
address. One of these shall be mailed to each Active, Fellow, and Honorary 
member of the Society, not less than forty days in advance of the annual fall 
convention. 

The voter shall then indicate on the ballot one choice for each office, seal the 
ballot in the blank envelope, place this in the envelope addressed to the secretary, 
sign his name and address on the letter, and mail it in accordance with the in- 
structions printed on the ballot. No marks of any kind except those above pre- 
scribed shall be placed upon the ballots or envelopes. 

The sealed envelope shall be delivered by the secretary to a committee of 
tellers appointed by the president at the annual fall convention. This com- 
mittee shall then examine the return envelopes, open and count the ballots, and 
announce the results of the election. 

The newly elected officers and governors of the general Society shall take office 
on the January 1st following their election. 

(6) The first group of vice-presidents, viz,, the executive vice-president, 
engineering vice-president, editorial vice-president, financial vice-president, con- 
vention vice-president, and a fifth governor, shall be nominated by the Board of 
Governors at its first meeting after the ratification of the corresponding provisions 
of the Constitution; and the membership shall vote on the candidates in ac- 
cordance with the procedure prescribed in these By-Laws for regular elections of 
officers so far as these may be applicable. 

By-Law VIII 

Dues and Indebtedness 

Sec. 1. The annual dues shall be fifteen dollars ($15) for Fellows and Active 
members, seven dollars and fifty cents ($7.50) for Associate members, and three 



April, 1943] CONSTITUTION AND BY-LAWS 263 

dollars ($3.00) for Student members, payable on or before January 1st of each 
year. Current or first year's dues for new members, dating from the notification 
of acceptance in the Society, shall be prorated on a monthly basis. Five dollars 
of these dues shall apply for annual subscription to the JOURNAL. No admission 
fee will be required for any grade of membership. 

Sec. 2. (a) Transfer of membership may be made effective at any time by 
payment of the pro rata dues for the current year. 

(&) No credit shall be given for annual dues in a membership transfer from a 
higher to a lower grade, and such transfers shall take place on January 1st of each 
year. 

(c) The Board of Governors upon their own initiative and without a transfer 
application may elect, by the approval of at least three-fourths of the Board, 
any Associate or Active member for transfer to any higher grade of member- 
ship. 

Sec. 3. Annual dues shall be paid in advance. All Honorary members, Fel- 
lows, and Active members in good standing, as defined in Section 5, may vote or 
otherwise participate in the meetings. 

Sec. 4. Members shall be considered delinquent whose annual dues for the 
year remain unpaid on February 1st. The first notice of delinquency shall be 
mailed February 1st. The second notice of delinquency shall be mailed, if neces- 
sary, on March 1st, and shall include a statement that the member's name will be 
removed from the mailing list for the JOURNAL and other publications of the 
Society before the mailing of the April issue of the JOURNAL. Members who are 
in arrears of dues on June 1st, after two notices of such delinquency have been 
mailed to their last address of record, shall be notified their names have been re- 
moved from the mailing list and shall be warned unless remittance is received on or 
before August 1st, their names shall be submitted to the Board of Governors for 
action at the next meeting. Back issues of the JOURNAL shall be sent, if available, 
to members whose dues have been paid prior to August 1st. 

Sec. 5. (a) Members whose dues remain unpaid on October 1st may be 
dropped from the rolls of the Society by majority vote and action of the Board 
or the Board may take such action as it sees fit. 

(b) Anyone who has been dropped from the rolls of the Society for non-pay- 
ment of dues shall, in the event of his application for reinstatement, be considered 
as a new member. 

(c) Any member may be suspended or expelled for cause by a majority vote of 
the entire Board of Governors; provided he shall be given notice and a copy in 
writing of the charges preferred against him, and shall be afforded opportunity 
to be heard ten days prior to such action. 

Sec. 6. The provisions of Sections 1 to 4, inclusive, of this By-Law VIII given 
above may be modified or rescinded by action of the Board of Governors. 

By-Law IX 

Emblem 

Sec. 1. The emblem of the Society shall be a facsimile of a four-hole film-reel 
with the letter S in the upper center opening, and the letters M, P, and E, in the 
three lower openings, respectively. The Society's emblem may be worn by 
members only. 



264 CONSTITUTION AND BY-LAWS [J. S. M. P. E. 

By-Law X 

Publications 

Sec. 1. Papers read at meetings or submitted at other times, and all material 
of general interest shall be submitted to the editorial board, and those deemed 
worthy of permanent record shall be printed in the JOURNAL. A copy of each issue 
shall be mailed to each member in good standing to his last address of record. 
Extra copies of the JOURNAL shall be printed for general distribution and may be 
obtained from the General Office on payment of a fee fixed by the Board of 
Governors. 

By-Law XI 

Local Sections 

Sec. 1. Sections of the Society may be authorized in any state or locality where 
the Active, Fellow, and Honorary membership exceeds 20. The geographic 
boundaries of each Section shall be determined by the Board of Governors. 

Upon written petition, signed by 20 or more Active members, Fellows, and Hon- 
orary members, for the authorization of a Section of the Society, the Board of 
Governors may grant such authorization. 

Membership 

Sec. 2. All members of the Society of Motion Picture Engineers in good stand- 
ing residing in that portion of any country set apart by the Board of Governors 
tributary to any local Section shall be eligible for membership in that Section, and 
when so enrolled they shall be entitled to all privileges that such local Section may, 
under the General Society's Constitution and By-Laws, provide. 

Any member of the Society in good standing shall be eligible for non-resident 
affiliated membership of any Section under conditions and obligations prescribed 
for the Section. An affiliated member shall receive all notices and publications 
of the Section but he shall not be entitled to vote at Sectional Meetings. 

Sec. 3. Should the enrolled Active, Fellow, and Honorary membership of a 
Section fall below 20, or should the technical quality of the presented papers fall 
below an acceptable level, or the average attendance at meetings not warrant the 
expense of maintaining the organization, the Board of Governors may cancel its 
authorization. 

Officers 

Sec. 4. The officers of each section shall be a chairman and a secretary- 
treasurer. The Section chairmen shall automatically become members of the 
Board of Governors of the General Society, and continue in such positions for the 
duration of their terms as chairmen of the local sections. Each Section officer 
shall hold office for one year, or until his successor is chosen. 

Board of Managers 

Sec. 5. The Board of Managers shall consist of the Section chairman, the 
Section past-chairman, the Section secretary-treasurer, and six Active, Fellow, or 
Honorary members. Each manager of a Section shall hold office for two years, 
or until his successor is chosen. 



April, 1943] CONSTITUTION AND BY-LAWS 265 

Elections 

Sec. 6. The officers and managers of a Section shall be Active, Fellow, or 
Honorary members of the General Society. 

Not less than three months prior to the annual Fall Convention of the Society, 
nominations shall be presented to the Board of Managers of the Section by a 
Nominating Committee appointed by the chairman of the Section, consisting of 
seven members, including a chairman. The Committee shall be composed of the 
present chairman, the past-chairman, two other members of the Board of Man- 
agers not up for election, and three other Active, Fellow, or Honorary members of 
the Section not currently officers or managers of the Section. Nominations shall 
be made by a three-quarters affirmative vote of the total Nominating Committee. 
Such nominations shall be final, unless any nominee is rejected by a three-quarters 
vote of the Board of Managers, and in the event of such rejection the Board of 
Managers will make its own nomination. 

The Chairman of the Section shall then notify these candidates of their nomi- 
nation. From the list of acceptances, not more than two names for each vacancy 
shall be selected by the Board of Managers and placed on a letter ballot. A blank 
space shall be provided on this letter ballot under each office, in which space the 
names of any Active, Fellow, or Honorary members other than those suggested 
by the Board of Managers may be voted for. The balloting shall then take place. 

The ballot shall be enclosed in a blank envelope which is enclosed in an outer 
envelope bearing the local Secretary-Treasurer's address and a space for the 
member's name and address. One of these shall be mailed to each Active, 
Fellow, and Honorary member of the Society, residing in the geographical area 
covered by the Section, not less than forty days in advance of the annual Fall 
Convention. 

The voter shall then indicate on the ballot one choice for each office, seal the 
ballot in the blank envelope, place this in the envelope addressed to the Secretary- 
Treasurer, sign his name and address on the letter, and mail it in accordance with 
the instructions printed on the ballot. No marks of any kind except those above 
prescribed shall be placed upon the ballots or envelopes. 

The sealed envelopes shall be delivered by the Secretary-Treasurer to his 
Board of Managers at a duly called meeting. The Board of Managers shall then 
examine the return envelopes, open and count the ballots, and announce the 
results of the election. 

The newly elected officers and managers shall take office on the January 1st 
following their election. 

Business 
Sec. 7. The business of a Section shall be conducted by the Board of Managers. 

Expenses 

Sec. 8. (a) As early as possible in the fiscal year, the secretary of each Section 
shall submit to the Board of Governors of the Society a budget of expenses for the 
year. 

(6) The treasurer of the General Society may deposit with each Section secre- 
tary-treasurer a sum of money, the amount to be fixed by the Board of Governors, 
for current expenses. 



266 CONSTITUTION AND BY-LAWS 

(c) The secretary-treasurer of each Section shall send to the treasurer of the 
General Society, quarterly or on demand, an itemized account of all expenditures 
incurred during the preceding interval. 

( d) Expenses other than those enumerated in the budget, as approved by the 
Board of Governors of the General Society, shall not be payable from the general 
funds of the Society without express permission from the Board of Governors. 

(e) A Section Board of Managers shall defray all expenses of the Section not 
provided for by the Board of Governors, from funds raised locally by donation, 
or fixed annual dues, or by both. 

(/) The secretary of the Society shall, unless otherwise arranged, supply to 
each Section all stationery and printing necessary for the conduct of its business. 

Meetings 

Sec. 9. The regular meetings of a Section shall be held in such places and at 
such hours as the Board of Managers may designate. 

The secretary-treasurer of each Section shall forward to the secretary of the 
General Society, not later than five days after a meeting of a Section, a statement 
of the attendance and of the business transacted. 

Papers 

Sec. 10. Papers shall be approved by the Section's papers committee previ- 
ously to their being presented before a Section. Manuscripts of papers presented 
before a Section, together with a report of the discussions and the proceedings of 
the Section meetings, shall be forwarded promptly by the Section secretary- 
treasurer to the secretary of the General Society. Such material may, at the dis- 
cretion of the Board of Editors of the General Society, be printed in the Society's 
publications. 

Constitution and By-Laws 

Sec. 11. Sections shall abide by the Constitution and By-Laws of the Society 
and conform to the regulations of the Board of Governors. The conduct of Sec- 
tions shall always be in conformity with the general policy of the Society as fixed 
by the Board of Governors. 

By-Law XII 

Amendments 

Sec. 1. These By-Laws may be amended at any regular meeting of the Society 
by the affirmative vote of two-thirds of the members present at a meeting who are 
eligible to vote thereon, a quorum being present, either on the recommendation of 
the Board of Governors or by a recommendation to the Board of Governors signed 
by any ten members of active or higher grade, provided that the proposed amend- 
ment or amendments shall have been published in the JOURNAL of the Society, 
in the issue next preceding the date of the stated business meeting of the Society 
at which the amendment or amendments are to be acted upon. 

Sec. 2. In the event that no quorum of the voting members is present at the 
time of the meeting referred to in Section 1, the amendment or amendments shall 
be referred for action to the Board of Governors. The proposed amendment or 
amendments then become a part of the By-Laws upon receiving the affirmative 
vote of three-quarters of the Board of Governors. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 



VOLUME XL ... MAY, 1943 



CONTENTS 

PAGE 

The Motion Picture Industry and the War Production 
Board C. M. TRAVIS 273 

American War Standard Specification and Descrip- 
tion of Color 277 

Motion Pictures and the War Effort J. G. BRADLEY 281 

Motion Pictures in Aircraft Production 

N. MATHEWS 291 

Sixteen-Millimeter Motion Pictures and the War Effort 

M. S. DAVID 296 

The M-G-M Recorder and Reproducer Equipment 
Units W. C. MILLER 301 



(The Society is not responsible for statements of authors.) 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

SYLVAN HARRIS, EDITOR 
ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 

** President: HERBERT GRIFFIN, 

90 Gold Street, New York, N. Y. 
*' 'Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
**Executive Vice-President: LOREN L. RYDER, 
5451 Marathon Street, Hollywood, Calif. 
^Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Avenue, New York, N. Y. 
** Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 
* Financial Vice-P resident: ARTHUR S. DICKINSON, 

28 W. 44th Street, New York, N. Y. 
**Convention Vice-P resident: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
^Secretary: E. ALLAN WILLIFORD, 

30 E. 42nd Street, New York, N. Y. 
*Treasurer: M. R. BOYER, 

350 Fifth Ave., New York, N, Y. 
Governors 

*H. D. BRADBURY, 411 Fifth Avenue, New York, N. Y. 
*FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*ALFRED N. GOLDSMITH, 580 Fifth Avenue, New York, N. Y. 
*A. M. GUNDELFINGER, 2800 S. Olive St., Burbank, Calif. 
*CHARLES W. HANDLEY, 1960 W. 84th Street, Los Angeles, Calif. 
*EDWARD M. HONAN, 6601 Romaine Street, Hollywood, Calif. 
*JOHN A. MAURER, 117 E. 24th Street, New York, N. Y. 
**WILLIAM A. MUELLER, Burbank, Calif. 

*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
**H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**JOSEPH H. SPRAY, 1277 E. 14th Street, Brooklyn, N. Y. 
**REEVE O. STROCK, 195 Broadway, New York, N. Y. 

*Term expires December 31, 1943. 
**Term expires December 31, 1944. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motion 
Picture Engineers, Inc., 20th and Northampton Sts., Easton, Pa., or Hotel Pennsylvania, New 
York, N. Y. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1943, by the Society of Motion 

Picture Engineers, Inc. 



THE MOTION PICTURE INDUSTRY AND THE WAR 
PRODUCTION BOARD * 



C. MERWIN TRAVIS** 

Summary. A brief discussion of the problems facing the motion picture industry 
through the scarcity of raw materials, and a few suggestions on the question of con- 
servation. 

In the production and distribution of motion pictures, film is ob- 
viously the most important single commodity. It may truthfully 
be said that on its continued adequate supply depends the life of the 
motion picture industry. We know how vitally interested all of you 
are in the present and probable future status of film during this emer- 
gency. It occurred to us that you might like to hear a little about the 
nature of film so that you may better appreciate the problems with 
which we all are faced. 

There are two main problems in connection with film and the 
necessity for its conservation through allocation. One is scarcity of 
raw materials, the other is plant manufacturing capacities. Nearly 
all 35-mm motion picture film is nitrocellulose base, the chief ingredi- 
ents of which are cotton linters, nitric acid, sulfuric acid, certain sol- 
vents, and plasticizers. This combination of raw materials comes 
very close to being gun cotton. In short, the manufacturer of motion 
picture film competes directly with the manufacturer of explosives. 
If there are not enough raw materials for both products we think 
you will agree that there can be no question as to which is the more 
essential. 

During the past year a terrific strain has been placed on our pro- 
duction of explosives, for remember that this nation must supply 
not only our own rapidly expanding Armed Forces, but those of our 
Allies the world over. This expansion in demand has so far out- 
stripped the supply. Every effort is being made to increase the sup- 
ply by the construction of new raw materials-producing facilities, but 

* Presented at a meeting of the Pacific Coast Section, Hollywood, Calif., 
February 11, 1943. 

** Unit Chief, Motion Picture and General Photographic Section, War Pro- 

Sduction Board. 
273 



274 C. M. TRAVIS [J. s. M. P. E. 

it does not seem that we can expect much relief for a long while to 
come. Without enough materials available for all nitrocellulose pur- 
poses, it became obvious last summer that their use in the less essen- 
tial products must be restricted. Accordingly the Motion Picture 
and General Photographic Section of the War Production Board is- 
sued Order L-178 on August 20, 1942, which placed 35-mm motion 
picture film under allocation. Since that date, as you all know, an 
amended L-178, much more restrictive, was issued on December 
31st. Under its terms reduced amounts of film are being made 
available to the motion picture studios and laboratories while in- 
creasing quantities are being channeled to the military services 
employing the film for combat and other purposes. 

Another problem that exists in connection with manufacturing 
film is the limitation of manufacturing capacities of the few manufac- 
tures of film base. This is illustrated best by the casting machines, 
so called because the mixture of materials (dope) is cast onto a series 
of precision-made, fixed-temperature heated rollers, and by this com- 
plicated process are made the transparent large-dimension rolls of 
photographic film base, which is later coated with various types of 
emulsions and cut to various sizes for the many ultimate uses. 
These machines, necessary to the manufacture of film base, are 
large, complicated mechanisms requiring some 15 to 18 months to 
manufacture and install, and call for the use of large quantities 
of critical metals and other materials in their making. These 
metals and materials are not available for this purpose, due, of 
course, to the demands for such materials in other more essential in- 
dustries. The demand by our Armed Forces and those of our Allies 
for aerial type film has resulted in a decrease in the normal manufac- 
turing capacities of these film-base manufacturers. This decrease of 
capacities is brought about by the necessary use of many of these 
film-casting machines to manufacture this special acetate base which 
has certain necessary characteristics not inherent in the nitrocellulose 
base most commonly used in 35-mm motion picture film. This aerial 
type film is used widely and generally for mapping purposes and for 
certain reconnaissance work. This acetate type base provides a film- 
base with less shrinkage qualities, which is desirable from the stand- 
point of accuracy, particularly in connection with mapping activities, 
and this base also has the non-inflammable properties also necessary 
for the uses to which it is being put. Likewise, making acetate-base 
film takes approximately four times the length of time required for 



May, 1943] MOTION PICTURES AND W. P. B. 275 

making nitrate-base film, hence the decreased production capacities. 

Therefore we have the two factors entering into the necessity for 
the allocation of 35-tnm motion picture film. First, the scarcity of 
the chief ingredients used in the manufacture of nitrocellulose-base 
film, and second, the loss of casting-machine base-manufacturing 
capacities, due to the increasing demand for the manufacturing of 
and the time involved in the making of the acetate type base aerial 
film. 

The question may arise as to what has been done about other types 
of film, those in general use by amateur, commercial, and professional 
photographers. Raw materials requirements for these products were 
cut by definite percentages as long ago as last spring through the 
Production Requirements Plan. Manufacturers and dealers absorbed 
the finished film inventories through last summer, and on December 
16, 1942, the War Production Board issued Order L-233 which defi- 
nitely controls the manufacture of film. Under its terms the produc- 
tion of 35-mm film, for other than preferred 'orders is set at 76 
per cent of the 1941 production. The allocation of this 76 per cent is 
handled under the terms of Order L-178. Ordinary amateur roll 
films and home movie films have been cut 50 per cent, while the 
professional type of sheet film has been cut 24 per cent. 

We believe that the motion picture distributors and producers have 
felt no loss in either the quality or quantity of the 35-mm film being 
produced for the motion picture industry. That this can occur is a 
tribute to American ingenuity and efficiency. Producers are making 
less film go farther by the elimination of wasteful and careless prac- 
tices. Exhibitors can help immeasurably in this conservation by 
keeping a watchful eye on projection equipment. If these machines 
are kept in perfect operating condition the life of release prints will 
be lengthened. It is in .this release-print footage that the largest 
saving can, of course, be made, and it is of the utmost importance that 
it be made. 

We are pleased with the manner in which the industry, particularly 
its technicians, has met the necessities of conserving the use of motion 
picture film. However, it has been called to our attention that further 
savings, though possibly small, may be made if the following practices 
were adopted: 

(1) Do not make any reprints of dailies or other viewing prints 
which are used entirely in production activities and never reach the 
public. 



276 C. M. TRAVIS 

(2) Use short ends in printing sound-track dailies, library mate- 
rial, sound-effects tracks, viewing prints of background material, and 
such other prints where the quality of the print has no bearing on the 
finished product. 

(5) Prevent accumulation of short ends by printing release prints, 
dailies, etc., with one splice to each reel (that is, splice the short end 
remaining from the printing of one reel on to the full roll of raw stock 
that will be used to print the next reel) . 

(4) Print without splices only those reels in which a splice may 
affect the quality of the finished product, such as dialog prints for 
re-recording, music prints for re-recording, and process plates for 
background projection. 

Another problem confronting all of us, and one that our office has 
been set up to work with and to assist the motion picture industry in 
meeting and coordinating their activities with the overall war effort, 
is the problem of priorities in connection with certain necessary ma- 
terials used by the industry for repair, maintenance, and operating 
supplies. This also involves motion picture set construction and the 
limitations on this type of construction. There is no doubt that many 
of you have been confronted with this particular problem in some 
form or another. When a situation arises where it appears necessary 
to ask for a priority in connection with obtaining a given material, 
each and every one of you should ask yourself whether or not that 
given material is absolutely necessary to the situation involved. 
You should ask yourself whether or not a substitute material could 
not be used one that is not a critical material requiring priority to 
obtain. We know this has been the practice and we mention it here 
merely as a matter of reemphasis. 

In closing, we want you to know that the importance of the mo- 
tion picture industry in the war effort is recognized by the War Pro- 
duction Board. Some 85,000,000 people depend upon it each week 
for a few hours' relaxation. It is one of our most powerful media for 
the dissemination of war news and public information. The industry's 
cooperation in making Government-sponsored films available to the 
public and in promoting the various war drives is very much ap- 
preciated. The industry has a definite place and a definite responsi- 
bility in this war effort. If every attempt is made to conserve vital 
materials such as motion picture film, we believe that the industry 
will be able to continue operations on a restricted but satisfactory 
basis. 






AMERICAN WAR STANDARD 
SPECIFICATION AND DESCRIPTION OF COLOR 



APPROVED JUNE 17, 1942, AMERICAN STANDARDS ASSOCIATION 
(ASA Z44-1942) 



FOREWORD 

For almost half a century, spectrophotometry has been the accepted method for the 
determination of those characteristics of an object which relate to its color. The Na- 
tional Bureau of Standards pioneered in this type of measurement and has continued 
its use as a primary method. 

Color standardization and specification for technical purposes have been an ac- 
complished fact for at least twenty years. The 1922 Report of the Colorimetry Com- 
mittee of the Optical Society of America codified and published a standard procedure 
based on scientific investigations carried out by leading investigators in this and other 
countries since the middle of the nineteenth century. In 1931 the International 
Commission on Illumination adopted essentially the same procedure, with details 
modified on the basis of the most recent and reliable investigations, incorporating 
almost completely the recommendations of the National Bureau of Standards and the 
British National Physical Laboratory. This system has been widely published, 
elaborated for convenience in practical applications, and extensively used during the 
past decade in academic and industrial laboratories both here and abroad. 

The chief criticism of this basic system of color specification has been due to its 
technical character, very little provision having been made for its interpretation in 
familiar terms. This limitation has been overcome in the present standardization by 
recognition of the correlation between the basic system and the useful and readily 
comprehensible system of colored samples embodied in the 1929 Munsell Book of 
Color. Reference to the Munsell Book of Color, supplemented by the basic specifica- 
tions of the colors exhibited therein, provides a convenient, readily comprehended 
interpretation of the basic specifications, and facilitates their visualization. This is 
especially important for those who are not familiar with the basic specifications of 
color. Used in this manner, the 1929 Munsell Book of Color bridges the gap between 
the aesthetic and qualitative comprehension of color employed by artists, designers, 
and the general public, and the basic specifications employed by and necessary for the 
purposes of science and industry. 

When a numerical specification of color is undesirable, the use of a correlated sys- 
tem of color names adapted from common language and proposed by the Inter-Society 
Color Council is recommended. This system of color names has been defined in terms 
of the Munsell system, and provides a literary method for the description of color 
where general comprehensibility is desired and precision is not important. 

277 



278 SPECIFICATION AND DESCRIPTION OF COLOR [j. s. M. P. E. 

i. PURPOSE 

To recognize and recommend a basic method for the specification 
of color, and to facilitate its popular interpretation. 

2. PROVISIONS 

2.1* The spectrophotometer shall be recognized as the basic in- 
strument in the fundamental standardization of color. [l]t 

NOTE : Specifications of the spatial distributions of the incident and collected 
light are essential to the standardization of spectrophotometry. Until standard 
conditions are established by agreement, the particular conditions employed in 
each instance should be stated clearly. 

2.2* Color specifications computed from spectrophotometric data 
shall be found by means of the standard observer and coordinate 
system adopted in 1931 by the International Commission on Illumi- 
nation. [2 ' 3 - 4] 

In the absence of a special reason for adopting some other illumi- 
nant in reducing spectrophotometric data, standard ICI illuminant C, 
representative of average daylight, shall be used. [2 ' 3>4] 

The basic specifications of color shall consist of the tristimulus 
value, Y, and the trichromatic coefficients, x and y, of the ICI co- 
ordinate system, or they shall consist of the tristimulus value, Y, 
and the dominant wavelength and purity. t3 - 4j 

NOTE: Dominant wavelength and purity are obtainable by computation f 3 - 4 ! 
from the trichromatic coefficients, x amd y. Several methods of expressing purity 
have been proposed and used to some extent. In this standardization, purity 
refers to the quantity which is called excitation purity in discussions f 4 ' 5 - 6 l of the 
several possible purity scales. For the sake of uniformity, the symbol, p, and 
expression in terms of per cent is recommended for purity. Likewise, when Y 
is specified in terms of reflection factor it should be expressed in per cent, symbol, 
R. It is customary to express dominant wavelength in millimicrons, /*, and this 
practice is recommended, together with the symbol, A. 

* The alternative, but coordinated systems of color specification described in 
2.1, 2.2, and 2.3 are each adequate for specification of color tolerance in those 
cases for which each system is useful and convenient. As in all engineering 
specifications, the tolerances in different industries vary and depend upon the 
uses for which the products are intended. Color specifications according to 2.2 
and 2.3 are, strictly speaking, appropriate only for products viewed by normal 
vision, but in the absence of agreement on standards for anomalous color vision or 
vision at low illuminations no more appropriate color specifications are available. 

f The single numbers in brackets throughout the text refer to "References." 



May, 1943] SPECIFICATION AND DESCRIPTION OF COLOR 279 

2.3* For the popular identification of color, material standards 
may be used. The only system of material standards that has been 
calibrated in terms of the basic specification is represented by the 
1929 edition of the Munsell Book of Color. [7 ' 8] The use of this book is 
recommended wherever applicable to the specification of the color of 
surfaces. Approximate identifications of Munsell hue, value, and 
chroma may be secured by direct visual comparison with the samples 
in the 1929 Munsell Book of Color. When the most accurate visual 
comparisons are needed, the mask method^ 91 is recommended. Wher- 
ever more exact Munsell notations are desired, they shall be found 
from the basic specification, Y, x, and y, by interpolation among the 
smoothed curves [10 ' nl for Munsell hue, value, and chroma. 

NOTE : Most surfaces whose colors fall outside the range covered by the samples 
of the 1929 Munsell Book of Color cannot be assigned Munsell notations by refer- 
ence to the smoothed curves. For such surfaces, for nontransparent media, 
and for illuminants, only the basic specification Y, x, and y, or Y, dominant wave- 
length and purity are recommended. 

2.4 A descriptive name according to the ISCC-NBS system of 
color designation^- 121 may be derived from the Munsell notation. 
This name is recommended wherever general comprehensibility is de- 
sired and precision is not important. The use of color names for 
color specification is not recommended. 

NOTE: It should be emphasized that the ISCC-NBS names are descriptive 
only and are not adapted to sales promotion onr intended to replace names that 
are developed for that purpose. 

REFERENCES 

1 ASTM Standard, Method of Test for Spectral Apparent Reflectivity of Paints, 
D 307-39. 

2 Proceedings, Eighth Session, Commission Internationale de VEclairage, Cam- 
bridge, England, September, 1931, pp 19-29. 

3 JUDD, D. B., "The 1931 I.C.I. Standard Observer and Co-ordinate System for 
Colorimetry," Journal of the Optical Society of America, Vol. 23, pp. 359-374 
(1933). 

4 HARDY, A. C., Handbook of Colorimetry, Technology Press, Cambridge, Mass. 
(1936). 

5 JUDD, D. B., "A General Formula for the Computation of Colorimetric Pur- 
ity," National Bureau of Standards Journal of Research, Vol. 7, pp. 827-841 (1941). 

6 MACADAM, D. L., "Photometric Relationships between Complementary 
Colors," Journal of the Optical Society of America, Vol. 28, pp. 103-111 (1938). 



280 SPECIFICATION AND DESCRIPTION OF COLOR 

7 Munsell Book of Color (standard edition with complete explanatory matter; 
abridged edition adapted for comparisons), Munsell Color Company, 10 East 
Franklin St., Baltimore, Md. (1929). 

8 GLENN, J. J., AND KILLIAN, J. T., "Trichromatic Analysis of the Munsell 
Book of Color," Journal of the Optical Society of America, Vol. 30, pp. 609-616 
(1940). 

JUDD, D. B., and KELLY, K. L., "Method of Designating Color," National 
Bureau of Standards Journal of Research, Vol. 23, pp. 355-385 (1939); RP 1239. 

10 NICKERSON, D., "Use of the I.C.I. Tristimulus Values in Disk Colorimetry," 
U. S. Department of Agriculture {May 1938) ; mimeograph copies obtainable on 
request. 

11 NEWHALL, S. M., "Preliminary Report of the O.S.A. Subcommittee on the 
Spacing of the Munsell Colors," Journal of the Optical Society of America, Vol. 30, 
pp. 617-645 (1940). 

12 NICKERSON, D., "Central Notations for ISCC-NBS Color Names," Journal 
of the Optical Society of America, Vol. 31, pp. 587-591 (1941). 



MOTION PICTURES AND THE WAR EFFORT* 
JOHN G. BRADLEY** 



Summary. Investigation of alleged war propaganda films by the Senate Sub- 
committee of the Interstate Commerce Committee in the fall of 1941 gave wide emphasis 
to the power of motion pictures. The Pearl Harbor incident changed the complexion 
of the public's attitude toward motion pictures and resulted in increased use of this 
medium in the war effort. Motion pictures are compared to other mediums of propa- 
ganda, such as the newspaper, the radio, the pulpit, and the comic strip. Under the 
stress of the war effort the word "propaganda" loses some of its stigma. Some of the 
motion pictures considered at the Senate's investigation are now being distributed 
widely with the Government's blessing. Nature of interest in motion pictures ex- 
plained. Represent direct approach to the mind through the eye and ear in a com- 
mon language. Power of motion pictures significant in terms of the millions of people 
who see them. Government use of motion picture films includes all branches of mili- 
tary service and auxiliary services, as well as the general American public, allied 
and neutral nations. 

The National Archives' principal interest in moiton pictures is that of preserva- 
tion and service. 

Early in the fall of 1941, the city of Washington was filled with 
prominent motion picture personalities, bent on a strange mission 
as later and rapidly developing circumstances ironically decreed. 
Bristling but business-like headquarters were set up in one of the 
leading local hotels and soon there were significant comings and 
goings, while the entire motion picture world watched and waited in 
a sort of edge-of-the-chair attitude. In the meantime the general 
public, somewhat concerned and not a little amused, cheered from the 
galleries as each favorite in this unique performance had an oppor- 
tunity to take a high note. 

No, it was not the President's birthday these people were cele- 
brating; that would not have been particularly strange. Nor was 
this array of talent producing a feature picture in the Washington 
locale; nothing quite so commonplace as that. This gathering repre- 
sented those who had come to the nation's Capital to defend the 

* Presented at the 1942 Fall Meeting at New York. N. Y.; received October 
30. 1942. 

** The National Archives Washington, D. C. 

281 



282 J. G. BRADLEY [j. s. M. P. E. 

freedom of the screen, just as their forefathers had defended the 
freedom of the press and the freedom of speech. More specifically 
they had come to Washington in response to an invitation from a 
Senate sub-committee of the Interstate Commerce Committee, ap- 
pointed to investigate alleged war propaganda films. Films listed in 
this category by the sub-committee were such pictures as Sergeant 
York, Confessions of a Nazi Spy, Escape, The Mortal Storm, Man 
Hunt, and many others. What happened during the hearings is now 
a matter of history but a significant feature of the affair is that the 
"defendants," by some strange magic, seemed suddenly to switch 
places with the "prosecutors." Veterans in publicity technique, they 
used the occasion as a headline under which they wrote their own 
story. They could not have bought the same advertising values; no, 
not for a million dollars. 

Suddenly the investigation stopped. The sub-committee ad- 
journed sine die. The delegates packed their brief cases and went 
home. 

Less than three short months later Washington was again filled with 
motion picture personalities; not necessarily the same people as be- 
fore, nor were they bent on the same mission. Furthermore, their 
stay has been longer this time for the reason that they are still in town 
and are coming and going in ever increasing numbers. As before, 
these people came in response to the Government's invitation, but 
not to plead for freedom of speech nor to defend alleged propaganda 
films. Quite the contrary is true; they are actually producing and 
distributing propaganda films with those in high places aiding and 
abetting their efforts. Or, if that statement sounds too harsh, let us 
say simply that they are producing and distributing films related to 
the war effort. Buildings are springing up, offices are being estab- 
lished, and technical equipment is being installed to accelerate the 
Government's far-flung motion picture program. In the meantime 
The Mortal Storm, Confessions of a Nazi Spy, Escape, Man Hunt, and 
others have gone to Latin America under the Good Neighbor policy 
with the State Department's blessing. And what brought about 
such a change in such a short time ? 

Pearl Harbor! 

Perhaps it would be more accurate to say that the Pearl Harbor in- 
cident precipitated the change. Actually the emotional concoction 
relating to propaganda was ready to jell at any sudden shock. Even 
at the Senate hearings there were those who stated boldly that if such 



May, 1943] MOTION PICTURES AND THE WAR EFFORT 283 

I 

and such pictures were propaganda then they were guilty of the accu- 
sation. Propaganda? Yes; why not? Basically there is nothing 
wrong with the word nor the phenomenon it represents. True, it 
may have been overtaken in bad company at odd times and become 
offensive to our peace time senses. Again, there are those who prefer 
to think of propaganda as something their enemies would be con- 
cerned with, but something entirely beneath their own dignity. 
Recognizing its power but still wanting to escape the stigma of the 
word, these same people have yanked a dozen synonyms from the 
dictionary in an attempt to have their cake and eat it. A rose by any 
other name would smell as sweet and propaganda under any synonym 
is still propaganda it is still a very potent weapon in the war effort. 

Perhaps a brief discussion of propaganda as it relates to the war 
effort might be interesting if not helpful. For example, the United 
States is made up of heterogeneous groups racial, religious, political, 
and other each springing from old world cultures, one or more genera- 
tions removed. A basic consideration of the American pattern is the 
tolerance that permits these differences to continue, and even to 
thrive. It represents differences without bitterness and without 
undue interference. If we do not like something, the instruments 
of persuasion and the ballot-box are open to us; but little more. 
Such a society offers many rewards, but it also imposes some penal- 
ties. For example, if persuasion or balloting is invoked to settle a 
difference of opinion, leisure is required. Even in peacetime such 
leisure may prove expensive but we are willing to pay the price. 
In wartime, however, we may not have the time to spare or we may 
be unwilling to pay the price; whereupon we delegate certain rights, 
including the adjustment of our differences, to others for the duration 
of the emergency. 

Under such a circumstance it is necessary to get wide acceptance 
of announced policies and appointed leaders quickly if we are to com- 
pete successfully with the enemy. This means that heterogeneous 
groups must be made homogeneous and that common territory must 
be discovered. This does not mean, of course, that I must start 
combing my hair as you comb yours or that John Doe must listen to 
the same radio program that John Smith likes. It does mean, how- 
ever, that we must have a crystallized community of interest which is 
capable of abnormal effort. If this be the case, which few will gainsay, 
what avenues are open to bring about such crystallization quickly 
and effectively? 



284 J. G. BRADLEY [j. s. M. P. E. 

Through argument we can point out that if we lose the war our 
economic system will suffer, our merchants will be driven off the seas, 
heavy taxes will be levied by the enemy, and in general our way of life 
will be dislocated. Through persuasion we can plead with our neigh- 
bors that we should make the war effort because it is the morally 
right thing to do, that we should help the weak and oppressed, and 
that we are our brother's keeper. In the name of patriotism we can 
talk about our national honor and the glory of our arms, we can re- 
cite the great battles our forefathers engaged in, and play martial 
music to incite love of country. Or, through fear and anger we can 
arouse the people to frenzied effort. And it should be remembered 
that just around the corner, twin brother to fear and anger, is hate. 

All these avenues lead to one meeting place. All these expedients 
lead to one objective organization of our national resources, whether 
the resources be physical, mental, or emotional. And the effort to 
bring about such organization appears to be a peculiar function of 
propaganda. This is no sacrilege; it is just common sense. We or- 
ganize our manufacturing efforts, our transportation, our distribu- 
tion, our finances, and man power. We approach such efforts as in- 
telligent adults and try to conscript the best talent available. But 
we blush slightly when it is suggested that we use the same intelligence 
toward organizing our emotions. 

A further word on hate. Organized love of country? That 
doesn't sound so bad. Righteous anger organized for action? That 
is understandable. But organized hate? That is a hard concept, 
even to put down on paper. It is a hard concept for the reason, as 
everyone knows, that hate, once unleashed, is like a plague, difficult 
to recall. Through hate you burn your neighbor's house and your 
own home is destroyed; you drink out of the wells you have poi- 
soned. That is why we cringe at the thought of organized and 
propagandized hate. For the very reason that hate is dangerous and 
breeds rapidly, efforts to organize our national emotional resources 
should be in the hands of wise leaders. In this respect the govern- 
ment has been most meticulous in making a sharp distinction between 
Nazi ideology and the German people; between things and persons. 
Thus, we may hate money changing in the temple but we need not 
necessarily hate money changers? Perhaps some will say that such 
a distinction becomes artificial in the heat of battle. Nevertheless, 
the admonition stands. 

If it be true, as argued herein, that we are and have been using the 



I 

May, 1943] MOTION PICTURES AND THE WAR EFFORT 285 

instrumentality of propaganda and, furthermore, that we should use 
it, let us examine briefly some of the forms of this weapon with particu- 
lar emphasis on motion pictures. The press, the radio, the pulpit, 
the statesman, the grocer across the counter, our neighbor all these 
are familiar mediums of persuasion in the total propaganda effort. 
Who has not suffered mortal agonies with Dan Dunn, Dick Tracy, 
Pat Ryan, Captain Easy, Daddy Warbucks, Scorchy Smith, and a 
host of other so-called comic strip characters? They warned us of 
fifth columns and spies, months before Munich. They built, in the 
realms of fancy, military weapons and techniques long before our 
bombers started coming off the assembly lines. But books, news- 
papers, magazines, sermons, radio programs, cartoons, and comic 
strips were accepted with concern or amusement as the case might be, 
but as normal phenomena. Then came Confessions of a Nazi Spy, 
The Mortal Storm, The Ramparts We Watch, and a dozen other motion 
pictures discussing the same situations which had already been dis- 
cussed by the press, the pulpit, the rostrum, and the radio ; and what 
happened ? A Senate Committee started an investigation. 

Why was this particular medium singled out? That question is 
difficult to answer. First of all, however, it might be said that the 
special consideration given motion pictures was a recognition of their 
power, a splendid compliment in itself. Up to that time most people 
had learned to accept the phenomena of motion pictures as a matter 
of course. Most of us had forgotten that we had not always had 
them, just as we have always had sunshine and air or debts and poor 
relatives. But as a result of this investigation, something happened 
and not without significance. 

It was said earlier in this discussion that the emotional concoction 
relative to propaganda was ready to jell at any sudden shock. By 
the same token it might be said that full recognition of the power of 
motion pictures was awaiting some public airing such as was given 
by the Senate sub-committee. For this the industry should be grate- 
ful. After all, the motion picture industry is relatively young. Less 
than a half century ago it was a slot machine or a peep-show affair. 
Less than forty years ago it was a nickelodeon business. Less than 
thirty years ago the first full-length American features were produced, 
in the period of The Birth of a Nation. Less than fifteen years ago 
sound pictures were referred to as the talkies. And all this time mo- 
tion pictures were thought of almost entirely as instruments of enter- 
tainment. 



286 J. G. BRADLEY [j. s. M. p. E. 

However, the motion picture was not content to exercise its option 
solely in the field of entertainment. Approaching adulthood and cut 
loose from some of its juvenile apron strings, it regarded the world 
as its laboratory and soon discovered that it could furnish informa- 
tion in successful competition with other mediums such as the printed 
page, and that few sources of knowledge were closed to its adventures. 
In making people laugh it learned it could make them think. Hence 
current events and natural phenomena were recorded, history was 
dramatized, and biographies were re-created. Through the in- 
strumentality of optics, electronics, double exposure, and animation, 
miracles were made believable and the subtlest fancies of childhood 
were made real. The oral, pictorial, and present-tense aspects of 
people and things acquired an immortality never before possible. 
Written history was given a sort of three-dimensional character and 
made a living thing for the first time. For example, printed reports 
tell us what people have said and done but such reports are at least 
once removed from reality. Motion pictures supply a primary 
knowledge of how things were said and done the eye and ear dimen- 
sion of recorded history. It is interesting to note in this connection 
that anything the human ear or a microphone can hear can be re- 
duced to photography and that all things visible can be reduced to 
sound, each with its own persisting pattern. Now one can actually 
see the sound of a diseased heart or of a discordant note in a piece of 
machinery, and reduce the profile of an oak leaf for the ear to hear. 

Out of this rich soil of opportunity sprang the newsreel, the travelog, 
educational and training films, and the expository film, to say nothing 
of the entertainment films which take on some of the characteristics 
of all the others. It was natural, therefore, that the motion picture 
industry should assume a major role in our lives, not only as a gigantic 
business but as a vital social force in mind-making processes. Week 
after week some 90,000,000 people go into our movie houses (and 
elsewhere) to see current motion pictures. Quietly, like the proverbial 
drop of water falling on a stone, the influence of these pictures affects 
the lives of the people so exposed to them. Dressed in the guise of 
innocent entertainment or otherwise made palatable by the story 
teller's art, such pictures are generally accepted without argument 
or dismissed with a yawn. In either case their influence can not be 
escaped. Mother comes to town the next day and buys a new hat. 
Father takes extra time at lunch and gets a new tie. Sonny Boy 
assumes an attitude and Mary Lou a pose. Old pronunciations are 



May, 1943] MOTION PICTURES AND THE WAR EFFORT 287 

discarded for new ones and old taboos are thrown aside. Gradually, 
through imitation or through stimulus to latent impulses, a change 
is affected. Sometimes this change is quite deliberate but more often 
than not it takes place without any conscious mental process. The 
very fact that one may not interrupt a motion picture to argue a point 
but is carried along swiftly in the current of its presentation makes one 
all the more vulnerable to its influence. It takes more vigilance than 
the average person possesses not to accept perfunctorily the evidence 
thus presented. 

The senators were right: a motion picture is a powerful thing. 
The recognition in this respect was well deserved. 

In the June, 1940, issue of The Journal of the Biographical Photo- 
graphic Association is an article written by this writer which dis- 
cusses in some detail the nature of the power of motion pictures. 
Brief quotations from that article seem in order here. 

"Many things contribute to the phenomenon of interest: novelty, 
surprise, movement, harmony, color, and so forth. Display of energy 
is another factor. Thus some people go to a football game who know 
nothing of the game. Nearly all of us will watch a great locomotive 
pass without knowing much about trains, for the simple reason that 
there is mass in motion and a display of energy. Still others will go 
to a football game or any game because they know the rules. In this 
case the interest is based on subjective imitation. They, as onlookers, 
are out there running interference. They are knocking the home run. 
It is their ace the partner trumps. They know the bonuses and penal- 
ties and hold their breath on the possibilities of a misplay. In motion 

pictures we have an imitation of life and in the common 

tongue. This time we all know the rules. We share the heartaches 
of the misunderstood. We punish the villain. We enjoy the luxury 
of the rich or share the poverty of the poor. We run, dance, sing, 

laugh, weep, pray and agonize with the make-believe people 

with whom we identify our own lives in a most powerful reality for a 
fleeting moment." 

In the case of The Mortal Storm, Pastor Hall, The Ramparts We 
Watch, and other such pictures currently being released the motion 
picture public identifies itself with a tragic reality and emotions are 
stirred deeply. No less a character than Death himself plays the 
Villain part and the drama this time transcends pure make believe. 

Since the investigators, the defendants, and the general public 
sealed to agree that motion pictures represent power, Pearl Harbor 



288 J. G. BRADLEY [j. s. M. P. E. 

brought this question into focus: What shall we do with this power? 
The Government answered promptly : We will use it. We will organize 
and utilize it in every possible way consistent with war effort policy. 
We will marshal it, direct its energies, and send it to serve on many 
fronts; pictures which tell of our way of life, of our resources, and of 
our faith in the pattern of things to come. Movies for the military : 
the Coast Guard, the Army, the Navy, the Marines, and the Air 
Forces. Movies for the home front: air-raid wardens, first aid 
groups, nurses, and fire fighters. Movies for the industrial front: the 
assembly line, the forgers, the tool makers, the riveters, those who 
bring up ore from out of the earth, and those who haul it over the face 
of the earth. Movies for those who go down to the sea in ships. 
Movies in a dozen languages for the neutrals who waver for lack of 
assurance one way or another. Movies for the allies who may be 
discouraged. Movies everywhere. The motion picture in uniform 
a swashbuckling young giant who slaps us on the back with self-assur- 
ance. An American giant who speaks in the vernacular. He is the 
Army, the Navy, and the Air Force rolled into one. He is the farmer, 
the merchant, the banker, the shipbuilder, and the manufacturer in 
composite. He is a giant who can do things a machine gun can never 
do and, furthermore, he can make machine guns less necessary. His 
is a bloodless conquest. One good motion picture, seen and ex- 
perienced, widely, like one good song which everyone sings, may have 
the force of a million soldiers. 

The strength of the American motion picture lies in the further fact 
that it is distinctly American. Unlike a painting or an opera imported 
from Europe the "movie" is largely the product of American imagina- 
tion, genius, and enterprise. It was grown in American soil or, more 
specifically, it emerged from our own basements, attics, and work 
shops, molded and fashioned in the American idiom; blood of our 
blood and sweat of our labors. Under such circumstances it is no 
wonder that motion pictures should play an important role in the 
mobilization of our material, mental, and emotional resources. 

It should not be assumed from the foregoing comments that the 
Government's interest in motion pictures started with the Senate in- 
vestigation referred to or that its interest in this respect is chiefly 
propaganda. This is definitely not the case. Some of the old-line 
Government agencies were producing films before the first World War. 
The Department of Agriculture, for example, has been sending out 
films on crop control, plant diseases, and other farm problems for 



May, 1943] MOTION PICTURES AND THE WAR EFFORT 289 

years. The Signal Corps of the War Department was engaged in ex- 
tensive motion-picture operations in connection with the first Ameri- 
can Expeditionary Force and has continued related activities ever 
since. In 1934, The National Archives establishment was organized 
with a special Division set up to preserve motion pictures (created by 
others) which reflect the American scene. In 1935 a survey indicated 
that there were approximately 17,000,000 feet of motion picture film 
in Government custody. By 1940 this volume jumped to some 
60,000,000 feet. Not only were new agencies finding good use of this 
new medium but the old agencies were finding new applications of it 
in the prosecution of their normal work. It is probable that even 
without a war-time stimulus the use of motion pictures by the Govern- 
ment would continue to pyramid, paralleling the growth of the in- 
dustry as a whole. 

This is true, however, that under the present stress, Government 
agencies concerned with film activities have geared themselves to 
the war effort. Little deviation from this policy is tolerated. Normal 
peacetime projects must wait. Only the very essential things such as 
preservation work can get official approval. The National Archives, 
for example, has accepted custody of valuable motion picture ma- 
terial. Its trusteeship requires that it keep its pledge to preserve such 
material against time. For example, it has among its accessions 
motion pictures of all the Presidents going back to and including 
Grover Cleveland. It has the exploration films of Admiral Byrd, 
Lincoln Ellsworth, and Charles Lindbergh. It has the Signal Corps 
film covering the first World War. Included in its collection are sound 
recordings of the President's speeches both on discs and on films, and 
many other priceless items. 

Even the preservation of this material has turned out to be war 
related and already The National Archives is a beehive of activity in 
terms of the present crisis. A Government agency asks, What have 
you on American soldiers in Siberia? The March of Time wires, 
What have you on Franklin Roosevelt in Europe during the first 
World War? Newsreel companies inquire, What have you on ship 
building 25 years ago? What have you on Douglas MacArthur? 
On Wainwright? On Stilwell? Eddie Rickenbacker? Glenn Mar- 
tin? That is as it should be. Government officials, script writers, 
directors, and searchers in general, avail themselves of these facilities. 
One day it may be a group of State Department people reviewing film 
for Latin-American distribution. Another day it may be Frank 



290 J. G. BRADLEY 

Capra, John Ford, or some other director sitting with Army and Navy 
Officers previewing an important release. Another day it may be a 
group of Chinese officials exhibiting motion picture material fresh 
from the far eastern front. Still another day it may be representa- 
tives from all the United Nations viewing film with a common inter- 
est. 

In terms of the foregoing program there will be many motion pic- 
ture films produced. Some of these are keyed for specific groups and 
may never reach the general public. Others, including those spon- 
sored by the Government and those produced independently, will be 
shown widely throughout the United States and the world. Aside 
from full length features, which will be numerous, are certain well 
constructed short subjects, pertinent to the all out war effort, some of 
which have already made their appearance on the public screen. In 
any event there will come out of this effort, material which will en- 
rich the library collection already started and perhaps future genera- 
tions will be grateful to those who are now taking the necessary steps 
to insure its preservation. 

On one of the giant statures in front of the National Archives 
Building is an inscription which reads, What Is Past Is Prologue. 
With this in mind many of the motion pictures which reflect the pre- 
sent, now being produced and distributed, will be preserved for the 
use of those who follow us when Yesterday must again be invoked 
to serve Today. 



MOTION PICTURES IN AIRCRAFT PRODUCTION* 

1 

NORMAN MATHEWS** 



Summary. A brief account of the use of motion pictures in the production of 
ircraft, for the training of pilots, and for various other uses. Some of the problems 
involved in the production of such pictures are briefly discussed. 
i 

The present war seems to be largely one of numbers and it is 
likely that victory will go along with the side having the greatest 
numbers of men, guns, tanks, ships, and planes. The story of air- 
craft production in this respect is well known ; the unheard of number 
of planes asked for by the President some time back is in fact becom- 
ing a reality, and it is said that the war of production is well on its way 
to being won. 

But having planes in sufficient numbers is only a part of the battle. 
There is needed, as well, the men to fly them, and equally important, 
trained mechanics to keep the planes in service. This war cannot be 
won by planes on the ground, no matter how great their numbers. 
For every plane in the air, three to twelve men are needed on the 
ground for its maintenance. The modern airplane is a complex ma- 
chine and to service it properly there must be trained personnel in 
sufficient numbers. 

Each branch of our armed forces was faced with the big job of 
training many men rapidly, not only in the maintenance of aircraft, 
but in every phase of modern warfare. A large share of this training 
job could be done by means of motion pictures. Although the United 
States Army was producing many training films dealing with aircraft 
maintenance, the Bell Aircraft Corporation believed that it, too, 
could help in this respect. 

The Bell Aircraft Corporation is a relatively young company, but it 
has some rather firm beliefs ; one of these is in the value of visual edu- 
cation. On the strength of this belief the Department of Visual Train- 

* Presented at the 1942 Fall Meeting at New York, N. Y.; received October 
15, 1942. 

** Motion Picture Division, Bell Aircraft Corp., Buffalo, N. Y. 

291 



292 N. MATHEWS Q. S. M. P. E. 

ing was organized a short time ago, and as a part of this there was cre- 
ated in April of this year a Motion Picture Division, whose first job 
was to be the production of an extensive series of training films, deal- 
ing with specific service operations on the Army airacobra, the P-39. 
As the number of combat aircraft of all types increased, so did the 
need for training adequate personnel for maintenance. This com- 
pany believed that motion pictures could do the job best in the 
shortest time, and since its Service Department had been in the field 
close to the problems of maintaining this one particular type of aircraft, 
it was from their experience that material could be drawn for the 
production of these films. 

To avoid possible duplication of effort, this work was to be coordi- 
nated with the Office of the Directorate of Individual Training of the 
Army Air Forces in Washington. The Bell Service Department drew 
up a list of some sixty-six subjects for which it felt instructional ma- 
terial was needed. The Army Air Force also submitted brief outlines 
for a series of subjects recommended for film treatment, and the two 
lists were nearly identical. 

The production of these films was to be closely coordinated with 
the Service Department. They had first-hand information as to 
which subjects were needed most urgently, and they were asked to 
draw up, in order of their importance, outlines of procedure for each 
operation. On the basis of these outlines, working scenarios were pre- 
pared by writers in the Motion Picture Division and upon completion, 
the scenarios were submitted to the Service Department and to the 
Office of the Directorate of Individual Training. Upon being ap- 
proved, they were put into production. 

The Motion Picture Division necessarily started out rather small 
and with a large job to do. Although the original agenda of sixty-six 
subjects had been consolidated into forty-five actual films, it was still 
a big job and time was an important factor. With the limited staff, 
it was not possible to departmentalize highly the work of motion pic- 
ture production, and it was necessary that each man be able to "double 
in brass." Thus, the sound man is also a cameraman, the cameraman 
cuts, and the directors write, cut, and even bloop effects tracks. The 
films were to be produced in 16-mm on black-and-white reversal type 
film, with a dupe negative for release printing. All phases of pro- 
duction, with the exception of laboratory work, were to be done in the 
department. 

Since only one airplane could be made available for demonstration 



. 
May, 1943] MOTION PICTURES IN AIRCRAFT PRODUCTION 293 

purposes, and since only one small corner of the plant could be set aside 
for the motion picture studio, a scheme was worked out to keep pro- 
duction constantly moving. The staff was arranged in alternating 
crews . During a period when one crew was shooting a picture, the other 
crews were either cutting a picture they had shot previously, or writ- 
ing scripts for subsequent films they would put into production. Thus 
all phases of production on a series of films were kept in constant mo- 
tion. A crew consists of a director, a cameraman, a script girl, and 
an electrician. When not shooting, the director prepares scripts he 
will later shoot. He supervises cutting and usually writes the record- 
ing script. In this way, he is able to follow a picture through the 
various stages of production from the first script to the final release. 
It has been found to be a very satisfactory working arrangement 
both from the standpoint of the individual and of the production 
program as a whole. 

The scripts prepared are not strictly shooting scripts, for with the 
intricacies of some of the operations, it is found that too much time 
would be required to prepare an accurate shot-by-shot script in terms 
of picture continuity. Rather, the scenario is an accurate account of 
the operation in terms of key shots. The actual picture continuity is 
worked out on the spot by the director. The cutting is done strictly 
in terms of picture continuity and the recording script is then written 
to the picture. When prepared for recording, the Service Department 
is called in to see the picture and hear the script for any possible cor- 
rection before recording; then again after recording, the first release 
print is screened by them for final O.K. before release. It was found 
in many instances that service operations could be done in quite a 
number of ways and for these films it was the job of the Motion Pic- 
ture Division to find the procedure best suited for instruction but at 
the same time acceptable to both the Service Department and the 
Army Air Forces. This was not always easy but in the final analysis it 
was worth the effort, since the films were to have something of a 
solidifying effect upon these procedures. 

It was found in some instances that sound could have a high instruc- 
tional value in these films. For example, there is only one way to 
judge when an adjustment on the landing gear clutch selector rod is 
correct ; that is by the sound made by two gears as they ride over one 
another when the electric motor is momentarily switched on. 

Another factor about which there has been considerable concern in 
the Motion Picture Division is the proper amount of intricate detail 



294 N. MATHEWS fj. S. M. P. E. 

to show in these films. These pictures are largely a matter of nuts and 
bolts. At the outset the Service Department advised that the more 
detailed the pictures were, the better, since they were to instruct men 
whose backgrounds were quite varied and very often bore little rela- 
tion to the job of maintaining aircraft. This advice was followed, but 
after a time the members of the Motion Picture Division themselves 
became a little weary with seeing large close-ups of cotter keys, safety 
wiring, split-end pins, and camloc fasteners. Aside from the pros 
and cons of too much detail, little was actually known as to how well 
the films already released were doing their job. It was decided that 
some kind of an evaluation was in order. 

A questionnaire was drawn up and sent out to service representa- 
tives who were using these films to instruct personnel at operational 
bases. Although the results of this questionnaire could not be con- 
sidered conclusive, they were some indication, and a number of ques- 
tions in the minds of the Motion Picture Division were answered, at 
least in part. It was found that the hunches about the amount of de- 
tail were wrong, according to the results of the questionnaire ; there 
was not too much detail. A number of other interesting things were 
learned as well : at least two showings of each film were recommended ; 
the films were considered to carry as much as three-fourths of the 
instruction required for a given operation; and the boys did not fall 
asleep while viewing the pictures. But of this there was some doubt, 
since a number of suggestions were made that more shots be included 
of guns firing and planes in flight. Judging also from the results of the 
questionnaire, the pace of the films was about right and the commen- 
tary was not too verbose. All in all, the films seemed to be doing a 
good job and invariably in the space on the questionnaire reserved 
for "remarks" there were requests for more films as quickly as possible. 

The distribution of these films is effected in two ways. The Bell 
Service Department has a number of service districts covering the 
various war areas, and the head of each district is equipped with a 
small sound projector and a complete set of these films. It is his job 
to see that the films do the most possible good in his district. For 
those areas which the Service Department does not manage to reach, 
the Army Air Forces can make up for distribution as many prints as 
are required, using the dupe negative with which they are furnished. 
At the outset some fifty or more prints were being made by the Army 
of each of these films, and by now that number may have increased. 
The films are now being designated as official Army training films. 



May, 1943] MOTION PICTURES IN AIRCRAFT PRODUCTION 295 

I 

The Army Air Forces often submit recommendations for the pro- 
duction of subjects which would be of value to their training pro- 
gram. Among these is a film on Pilot Indoctrination dealing with the 
check-out procedure for pilots on the P-39. This film, recently com- 
pleted, has been released and it is planned to be used in conjunction 
with the Air Force's recently organized safety campaign designed to 
reduce the number of accidents. They feel that more accidents could 
be avoided were there more information available regarding the oper- 
ation and performance of the various types of aircraft. This film is 
intended for the advanced pilot, and its purpose is to point out the 
characteristics and features of our plane so far as it differs from 
others he has flown. In production now is another film requested 
by the Army Air Forces dealing with daily inspection of the P-39. 

In addition to the Service Training Films, it is felt that there is a 
great deal that instructional films can accomplish in other directions. 
It is planned in the near future that the work of the Motion Picture 
Division will be expanded to include industrial training, for which 
there is an urgent need today in the aircraft industry, with its rapid 
expansion and the introduction of new methods of fabrication. 

In establishing the Motion Picture Division as part of its organiza- 
tion, the Bell Aircraft Corporation believed it would thus be able to 
produce better films quicker and at less cost. As the only aircraft 
company maintaining its own film unit, the project has proved itself 
highly successful. 



SIXTEEN-MILLIMETER MOTION PICTURES AND 
THE WAR EFFORT* 



MICHAEL S. DAVID : 



Summary. A brief account of the production and applications of 16 -mm 
motion pictures by the General Motors Corp., especially in connection with the 
speeding up of production of war materials. 



Sixteen-millimeter photography has always enjoyed a great deal 
of popularity among the so-called amateurs. It is true that a few 
organizations had their own small production units, and, scattered 
throughout the country, there were a few studios that devoted all 
or part of their time to producing 16-mm commercials; however, 
professionally speaking, 16-mm photography was more or less in 
the growing stage. It is also true that a great many 35-mm so-called 
"business movies" had been reduced to 16-mm release prints, but 
direct 16-mm photography and sound recording was still struggling 
in "knee pants," that is, as far as volume production was concerned. 

However, with the advent of the United States into the war and 
the subsequent transformation of industry from peacetime to wartime 
production, new fields were opened for 16-mm films. Now, defense 
production was the big job. New and unusual products must be 
manufactured in great quantities and with as much speed as possible. 
Hundreds upon hundreds of thousands of production workers must 
be taught practically overnight to handle precision equipment. 
Without question, there was now a burning need for training ma- 
terial of all types. So film producers followed the example set by 
industry; and sales training and sales promotion films were forgotten 
for the duration, and defense training films took their place. 

Manufacturers, who had been keenest competitors in the old order 



* Presented at the 1942 Fall Meeting at New York, N. Y.; received October 
27, 1942. 

** General Motors Corp., Photographic Section, Detroit, Mich. 

296 



16-MM PICTURES AND THE WAR EFFORT 297 

I 

of business pooled their knowledge and experience in a series of 
training films designed to instruct men and women who were absolute 
strangers to their new jobs. 

This was especially true in the automobile industry. Several 
companies that had been producing steel bodies for cars changed 
almost overnight to the production of aircraft wings and fuselages. 
Obviously, the workmen had to be taught to perform new tasks 
with different materials. For example, the radical change from 
sheet steel that could be handled with a reasonable amount of abuse 
to soft duralumin, where a scratch or dent meant the scrap heap 
or hours of precious time lost, indicated the need for educating the 
men to this new problem. 

Since time was the all-important factor, it was impossible to 
teach the workers their new operations individually, and a series of 
16-mm black-and-white sound pictures were produced. In these 
films elementary operations had to be treated as if they were new sub- 
jects : simple operations such as how to drill a hole, the proper way 
to use a file or pair of tin snips, or the use of the riveting hammer old 
operations, but new techniques. These films were shown at regularly 
scheduled classes until the men became thoroughly familiar with 
their new jobs. 

There are, of course, many other instances of the wide use of 
visual training through 16-mm productions throughout the country. 
Semiskilled workmen are being trained to handle precision equip- 
ment, and new problems are being solved in a simple, straightforward 
manner. 

In an effort to speed up war production, some of the more pro- 
gressive manufacturers are now using 16-mm film for job analysis. 
In the process of production changeover it is sometimes difficult to 
devise the quickest and simplest methods of handling certain opera- 
tions. However, the use of photography simplifies job analysis 
by enabling the manufacturers to study the pictures in a continuous 
projector, and so eliminate the workers' unnecessary movements, 
and devise new and faster techniques of material handling. 

In some instances where identical operations are being duplicated 
by manufacturers in widely separated factories, 16-mm films are 
being used to good advantage. This is especially true on difficult 
operations where a great deal of time has been spent to simplify the 
techniques. Films are made showing the improved methods; 
they are sent to plants doing the same job and are shown to the 



298 M. S. DAVID [J. s. M. P. E. 

workers. Much valuable time is saved, since there is no duplication 
of effort in trying to solve identical problems. 

With many industries working around the clock, Sundays and 
holidays, the necessity of keeping the production worker interested 
in his specific operation and impressed with the importance of speed 
and accuracy is quite a problem. Here is an instance where a 
morale type of film accomplished more good than a dozen pep talks 
might have done : 

The production of cannon at a certain plant was being held down 
due to the shortage of parts being produced by sub-contractors. 
The plant depended for a great deal of its material on these out- 
side sources nuts, bolts, and other seemingly unimportant parts so 
essential to the finished cannon. Inasmuch as most of the sub- 
contractors' employees had no idea of what the finished product, 
to which they were contributing, looked like, the management felt 
that if the people who made these parts could be shown just how 
important their contribution was they would have less difficulty in 
meeting their quota. Subsequently an interesting sound Koda- 
chrome picture was produced, showing the production and assembly 
of the cannon as well as the completed cannon in action. The 
film was shown to the employees of each sub-contractor, and the 
response from each audience group left no doubt in the plant man- 
ager's mind as to how much cooperation he could expect in the 
future. This is but one instance where a 16-mm film has given the 
needed boost in morale. Many organizations are using them 
periodically as part of their scheduled visual training programs. 
Probably one of the least publicized, yet most important, uses of 
16-mm film in photography is in engineering research. Usually lack- 
ing in photographic quality and professional embellishment, such 
films nevertheless play an important part. Engineers are finding them 
of great value, since the results of tests, photographed, may be 
studied again and again, and then filed for future reference. 

Test pilots also find that a 16-mm camera can be used to great 
advantage when putting a new model ship through its paces. Here- 
tofore, when a test pilot took up one of the planes, he was expected 
to keep notes, while he was flying, of all the data pertaining to the 
plane's performance. In the 9-G power dive it is next to impossible 
to retain consciousness, let alone write down instrument readings. 
It is during this test, in particular, that photography -plays a big 
part. With the aid of a compact 16-mm camera mounted over the 



May, 1943] 16-MM PICTURES AND THE WAR EFFORT 299 

pilot's head, all the valuable information on the instrument dials 
is photographed while the ship is in flight, resulting in more complete 
and accurate data than the best pilot could ever hope to do with 
his pad and pencil. 

Another, and probably more common, use of 16-mm film in re- 
search is its application to ultra-high-speed photography. Some of 
the more enterprising research groups have enlisted the aid of the 
high-speed camera in an effort to analyze the action of objects 
moving too fast for the eye to see. One producer of automatic 
cannon found it a tremendous help in studying the action of the 
recoil spring when the cannon was firing at speeds of several hundred 
shells a minute. Another used it to good advantage in studying 
the action of caterpillar treads on a fast moving tank. In this case, 
close-up detail in ultra-slow motion was necessary if an accurate 
analysis was to be made. 

These are, of course, only a few examples of how 16-mm photog- 
raphy is being put to use in the interest of engineering research. 
However, the field is wide and varied and every day the camera is 
being applied in some new way. 

Undoubtedly, the successful duplication of sound Kodachrome 
prints is greatly responsible for the increased use of direct 16-mm 
photography in the war effort. Many subjects that lack interest 
or do not tell a complete story in black and white are being success- 
fully photographed in Kodachrome. A good example of such a 
situation is a recent series of fine training films on arc welding.' 
Here, the actual arc is photographed, and it is possible to see the 
action of gas, arc, slag, and molten metal, each an important item 
in the art of welding. It is obvious why the choice of color-film 
in this case was a happy one. 

The aircraft industry is also making the most of Kodachrome in 
visual education programs. Training films dealing with wiring, 
fuel, and oil lines are being handled very successfully in color. The 
problem of locating accurately the proper wires or tubes that go 
to make up the maze of controls on the average combat plane is 
simplified, since each wire or tube is a specific color or combination 
of colors. Kodachrome films dealing with this phase of the training 
program tell the complete story at a glance. These are but a few 
of the many applications where 16-mm Kodachrome is doing an ex- 
cellent job in helping to speed up the war effort. 

However, there is one use for Kodachrome film that does not 






300 M. S. DAVID 

directly affect war production but is nevertheless very interesting. 
That is in the art of camouflage. Looking ahead to the day when 
it may be necessary to camouflage its vital industrial plants to 
protect them from enemy bombardiers, one organization in particular 
is making the most of Kodachrome photography. They are con- 
structing miniature models of their plants, applying different types 
of camouflage, and then, literally flying over them with color cameras, 
determine the most effective method of camouflage to use. When 
one stops to consider the tremendous task it would be to attempt 
such an experiment on a full scale one can not help appreciating 
how practical is the use of 16-mm Kodachrome photography and 
miniature models in this work. But then this, too, is only another 
of the new fields in which direct 16-mm photography is playing an 
important part. Practically every day it is being put to some new 
use in an effort to help in the prosecution of the war. 



THE M-G-M RECORDER AND REPRODUCER EQUIPMENT 

UNITS* 

WESLEY C. MILLER** 

Summary. Film recording and reproducing equipment has recently been de- 
veloped for the sound replacement program of the Metro-Goldwyn-Mayer Studio. 
The completion of the program is of course indefinitely delayed because of the war 
situation, but the apparatus design had previously been brought to the stage of finished 
pilot models. 

Quality of product was the primary design criterion although it was found prac- 
ticable to meet optimum quality requirements and at the same time keep cost and 
difficulty of installation and maintenance at a minimum. 

The apparatus integrates all the many developments that have long been standard 
practice in Metro-Goldwyn-Mayer motion picture sound production, and in addition 
provides many new features of additional value. 

In the course of the development of the equipment used by these 
studios for sound recording and reproducing, many design improve- 
ments have been made during the past few years. New principles 
have been evolved and many new apparatus units and equipment 
groups have been developed which have made valuable contributions 
to the quality of the sound product as well as to the efficiency of 
production handling in use. A study of available types of apparatus 
; seems to indicate, however, that in many instances the improvements 
have been made only as additions or modifications of existing ap- 
paratus units. There has been a need for new basic designs in- 
corporating the best quality-producing features at a reasonable cost 
and in forms properly adaptable to modern studio requirements as 
they are governed by space, personnel, and production methods. 

For some time plans have been under consideration for modernizing 
the MGM sound department plant to replace certain obsolete 
equipment and to provide expanded facilities to accommodate in- 
creasing demands. While much of this will take place in improve- 
ment of the re-recording plant, which has been heavily overloaded 
for some time, other parts of the plant will be similarly affected. 






* Received May 15, 1942. 
** Metro-Goldwyn-Mayer Studios, Culver City, Calif. 

301 



302 



W. C. MILLER 



[J. S. M. P. E. 



Thus the problem of the selection of proper apparatus units and of 
the most useful equipment layout becomes very important. 

Study of existing types of film machines, both recording and re- 
producing indicated that there was nothing available commercially 
that even partially met all the requirements imposed by this and 
other studios. Cost was naturally an important item, but even 
disregarding it, the quality and operational features that are required 
were not available in suitable combinations. Consequently, arrange- 
ments were made to undertake the design of certain new units, 




22 



REPRODUCERS 



FIG. 1. Equipment layout for re-recording room. 



together with the design of a complete recording and reproducing 
system that would combine these new units with existing apparatus 
that did fit into the picture. This design work has proceeded with 
the active cooperation of Electrical Research Products, Inc., and 
has reached the point where pilot models of some of the proposed 
equipment units are complete. Progress on the full program will of 
course be retarded by the war situation to the extent that certain 
features may necessarily be indefinitely postponed. 

Two basic equipment types are involved, a recorder and a re- 
recorder. These are designated, respectively, as the RA-1102 re- 
cording machine and the RA-1092 re-recording machine. They may 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



303 



be readily grouped in any suitable manner to meet production 
requirements. 

The arrangement which is proposed for the Metro-Goldwyn- 
Mayer re-recording department is indicated in Fig. 1. This was 
chosen as a convenient means of associating each group of reproducers 
with the recorder normally used with it, while at the same time 
facilitating the use of additional reproducers from adjacent groups 
when required. Much of the power supply is contained in the 
cabinets forming part of the individual units, with the remainder 
in other parts of the building already devoted to power equipment. 




FIG. 2. Recorder and reproducer units, typical mounting. 



It will be noted that the suggested arrangement affords optimum 
operating and maintenance spacing as well as simplicity of initial 
installation. 

The individual machines are mounted as permanently integral 
parts of their supporting sheet-metal tables, which are in turn ar- 
ranged to mount beside each other in any combination in much the 
same form as a series of conventional filing cabinets. Meters and 
controls relating to each machine are in panels in its table. Other 
electrical equipment, such as relays, light-valve feed-back and noise- 
reduction circuits, lamp supply and control, connected to each 
machine is also mounted in the table and permanently connected to 
the machine and controls (Fig. 2). Interconnection of the tables 



304 



W. C. MILLER 



[J. S. M. P. E. 



and connection to the central plant are made by busses running 
through the floor under the tables and ending at terminal blocks in 
each table. Certain electrical units, such as the plate- voltage supply 
and power-line voltage-regulator, are mounted either in remote 
locations or in table sections at the ends of the bays, as these supply 
units are common to, and supply all the recorder and reproducer 
units. If at any time complete replacement of a unit is required, 
or possibly a revision of the layout of part of the room, whole table 
units are quite readily disconnected and removed. 




FILM DRIVE SCHEMATC 

FIG. 3. Film motion diagram. 



Film Motion. Before going into a description of the details of the 
machine and table units, attention is invited to the film motion 
mechanism around which the machine designs are centered. This 
is identical in the recorder and reproducer, and is the type of move- 
ment for which a Scientific or Technical Award was made in 1927 
to Douglas Shearer and the Metro-Goldwyn- Mayer Sound Depart- 
ment by the Academy of Motion Picture Arts and Sciences. It 
provides not only the maximum approach to uniformity of motion 
that has been commercially attainable, but it does it by methods 
that have kept the construction and probable maintenance cost well 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



305 



below that of any machine thus far available. Moreover, a great 
deal of attention has been devoted to ease of handling, film threading, 
and the many operational features necessary for rapid production. 

The operating principle is shown in Fig. 3, and its practical appli- 
cation in Fig. 5. The film runs past the optical centerline or recording 
axis on a drum which is rigidly connected to a flywheel having con- 
siderable mass. The drum and flywheel are kept in motion by the 
film tension which is provided by the tension roller. Both entering 
and leaving ends of the film are driven by a sprocket, which in turn 
is driven from the main driving source through a light adjustably 





;ONTACT PONT 



FIG. 4. Dual-pitch diameter sprocket. 

damped spring. The drum and flywheel are designed to rotate with 
a minimum of friction, all damping in the filter system being applied 
at the spring-driven sprocket element. 

Thus the flywheel tends to rotate at uniform velocity. Any varia- 
tions that might occur due to film irregularities of shrinkage, perfora- 
tion, etc., or to irregularities in the drive of the filter sprocket are 
eliminated by the latter before they can have any effect upon the 
flywheel rotation. Consequently the flywheel and drum run at a 
velocity that is essentially perfectly uniform. The film is held 
tightly to the drum by the tension created by the tension roller, 
and hence its velocity is equally constant. In practice the speed 
variation or flutter content of the film is readily maintained at values 
below 0.06 to 0.07 per cent. 



306 



W. C. MILLER 



[J. S. M. P. E. 



Further study is now being made of the possibility of including in 
the flywheel some form of hydraulic damping mechanism. This will 
require modification of the sprocket damping and of the flywheel 
assembly, but it appears to reduce further the low-frequency speed 
variation below the present low and satisfactory value. 

Attention is invited to the design of the 32-tooth filter sprocket. 
Film work is being done at both top and bottom of the sprocket and 
with tension on the film from the effect of the jockey roller. The 



ER SPROCKET 




FIG. 5. Recorder; modulator and film compartments. 



entering tooth should be in contact at the top and the leaving tooth 
should be in contact on the bottom. To produce this condition a 
sprocket pitch diameter must be chosen that will provide both 
conditions. A simple analysis will show that this is an impossible 
requirement, particularly over any reasonably extensive range of 
film shrinkage variation. Thus a compromise value of sprocket pitch 
diameter would have to be accepted. If, however, a design were 
possible where the pitch diameter in one direction is of one value and 
in the other direction is another value, each of these values may be 
chosen to accommodate exactly each of the two requirements. 






May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



307 



Such a sprocket is shown in Fig. 4. It is evident that the pitch 
diameter of the sprocket is of a different value depending upon the 
direction of film pull. The existence of the slight hump in the tooth 
has no effect other than the one it is supposed to have, and the entire 
operation of the sprocket is extremely good. 

Moveover, its manufacture 
is very simple. Using a stand- 
ard cutter, a cut is made to the 
smaller pitch diameter. The 
cutter is then backed off by an 
amount equal to the difference 
of the two pitch radii, and 
shifted circumferentially the re- 
quired amount to provide the 
proper tooth pitch spacing. The 
idea was evolved by Mr. Carlos 
Rivas of the MGM sound de- 
partment (Fig. 5). 

This method of film drive 
lends itself to construction forms 
that are simple and inexpensive. 
Inasmuch as the film drives the 
flywheel, there is no other me- 
chanical connection between the 
filter sprocket and the flywheel. 
Thus the only mechanical drives 
required are those for the filter 
sprocket and the two utility 
sprockets pull-down and hold- 
back and, of course, a drive 
for the take-up at the lower 
magazine. Through the expedi- 
ent of using silent chain (see 
Fig. 9) instead of the conventional gears, a simplified and inexpen- 
sive construction is obtained. Moreover, and of great importance, 
the drive motor itself is directly coupled to the filter sprocket 
shaft thus eliminating an additional set of gears. To accomplish 
this a special type of motor has been designed, which runs at 180 rpm 
when interlocked to a distributor running at 720 rpm. For synchro- 
nous operation a 48-cycle, 180-rpm synchronous motor is available. 




FIG. 6. Recorder unit; front. 



308 W. C. MILLER [j. s. M. P. E. 

Each of the sprocket units, namely, pull-down, hold-back, and 
motor-filter sprocket, is a separate assembly. The drum-flywheel 
unit is similarly an individual assembly. These assemblies mount 
on a vertical wall with no accurate spacing required between them 
although their approximate relationship should be maintained. If 
now a housing is built around this wall to cover the apparatus and 




FIG. 7. Recorder unit; front, covers open. 

to provide a compartment for the optical system, the machine is 
complete. This is the basis of the whole design and as such it 
appears completely to meet the requirements (Fig. 6) . 

It will be noted from the figures that on both the recorder and the 
reproducer the magazines are mounted vertically, that is, with the 
feed magazine on top and the take-up magazine underneath the 
machine in much the same position as on the conventional type 
of picture projection equipment. From the standpoint of space 
economy and facility in threading film, this magazine arrangement is 



RECORDER AND REPRODUCER EQUIPMENT 



309 



;May, 1943] 

. 

clearly superior, particularly for apparatus that is to be permanently 
mounted in one position. Moreover, because of MGM's standard 
split-film technique, separate feed and take-up magazines are essen- 
tial and the vertical mounting further aids in this purpose. 

Recorder. The recorder unit is shown in Figs. 6, 7, and 8. It 
combines the recording ma- 
chine, its table and all the 
operating controls, noise-re- 
duction, and current-supply 
apparatus directly associated 
with it in operation. The re- 
cording machine itself is a 
single housing divided into two 
comparttr ents, each with proper 
doors for access in operation 
and maintenance. The right- 
hand compartment contains the 
film-driving mechanism pre- 
viously described and also that 
part of the optical system that 
produces the squeeze mat. 1 
This will be described in de- 
tail later on. The left-hand 
compartment houses the modu- 
lator unit. Inasmuch as there 
is always the possibility of a 
complete revision of modulator 
principle or design, provision 
is made for the use of a sub- 
apparatus assembly, which can 
be removed as a unit in case 
of major changes. 

For the purposes of the first 
model, the modulator assembly shown in Figs. 9 and 10 was designed 
around the standard ERPI light- valve and the 4:1 optical system 
normally used with it to produce a nominal 100-mil standard variable- 
density track. Provision is made for the use of either tungsten or 
mercury- vapor light-sources, as each has value for specific purposes. 
Figs. 10 and 11 show a tungsten lamp in position, while Fig. 12 shows 
a rear view of the modulator compartment with a mercury- vapor 




FIG. 8. Recorder unit; rear. 



310 



W. C. MILLER 



[j. S. M. P. E. 



lamp in place, surrounded by its opaque glass housing through which 
cooling air is drawn. This phase of the use of the mercury- vapor 
lamp is discussed later. 

An examination of these figures, together with Fig. 13 which shows 
schematically the details of the optical system, will show that opti- 
cally the unit is essentially identical with the system described by 
Dupy and Milliard. 2 It consists of a condenser which focuses the 
light-source on the light- valve, and an objective which in turn 
focuses the light-valve image on the film through a small cylindrical 



DUST SEAL 




FIG. 9. Recorder; modulator unit. 



lens close to the film, which serves further to reduce the image height 
and thereby minimize intermodulation products. One departure 
from the conventional arrangement is the use of a 45-degree mirror 
between the light- valve and the objective lens which folds the system 
at right angles into the rear of the modulator compartment. This 
has no effect upon operation, but it does permit a reduction in the 
overall length of the recorder and utilizes what would otherwise be 
unused space in the housing. 

No provision is made for photoelectric-cell monitoring as this has 
not been used by MGM for several years. However, it could be 
installed with no difficulty. A visual light-valve monitor is provided 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 311 



instead. A very small hole is made in the mirror surface of the 
45-degree reflector. Back of this a small lens focused on the light- 
valve ribbons throws up an image of the latter on a small ground- 
glass on the left front door of the machine. The small tube pro- 
jecting through the 45-degree mirror housing in Fig. 9 is the mounting 
for this monitoring lens. This visual monitor gives a very effective 
means of ascertaining the condition of the light- valve at all times. 

Between the mirror and the objective lens is inserted the syn- 
chronizing shutter which also provides a means of checking exciter 
lamp illumination in terms of a photoelectric-cell reading. Reference 




FIG. 10. Recorder; modulator unit, valve removed. 

to Fig. 12 will give an idea of this operation. Before and after a 
take, the shutter is in the position shown in the figure and all the 
light from the light-source and valve is reflected from the mirrored 
surface of the shutter up to the photoelectric cell. Readings of the 
light with the light- valve in or out of position, or with or without 
bias, give a very reliable check on the light-valve condition and on 
the illumination of the film, and give more nearly uniform results 
than the conventional lamp-supply measurements. Just after the 
take starts and the recorder is up to speed, the shutter is automati- 
cally snapped down out of the way of the light-beam so that the 
latter reaches the film without obstruction. Similarly, after the take 
is finished the shutter is released and closes. The opening and closing 
of the shutter and the consequent beginning and end of the sound- 



312 



W. C. MILLER 



[J. S. M. P. E. 



track exposure provide synchronizing marks before and after each 
take. The entire shutter and photocell mechanism is mounted as 
an integral part of the objective lens assembly as shown in Fig. 9. 

MGM has used the squeeze mat on release prints for a number of 
years. The original method of providing the mat was to print it on 
in the final release-printing operation. Subsequently an improve- 
ment was made by inserting an adjustable mask ahead of the light- 








FIG. 11. Recorder unit ; rear, covers removed. 

valve and introducing an auxiliary condenser system which focused 
the mask on the latter. More recently a new method has been in- 
volved which has been working so satisfactorily that it promises to 
be the finally accepted one. A thin mask or mat is mounted close to 
the film at the optical centerline (approximately 0.006 inch from the 
film) and a calibrated F-slot in this mat intercepts the sides of the 
beam coming from the light-valve. The shadow cast on the film by 
the mat eliminates exposure on the negative and leaves only the 






May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



313 



width of track corresponding to the open section of the F-slot. The 
! F-slot mat itself is adjustable vertically by a small selsyn motor which 
is controlled by the mixer, who is thus able to move the mat up and 
down to provide any desired amount of squeeze effect at will. For 
threading purposes, the F-slot mat-holder is swung away from its 
operating position by a small cam working against a spring. The 
small cylindrical lens which forms part of the optical system is also 
mounted in the mat-holder so that it is moved away from the film 
during threading, while the whole assembly snaps back in place when 



SILENT Cs-iAIN OFUV 




FIG. 12. Recording machine; rear. 



the cam is released. The mounting arrangement for the mat device 
and lens holder is such that original lens focus is readily obtained and 
that the assembly always returns positively to the same position. 

Reference to Fig. 5 will show the mat device mounted directly to 
the left of the recording drum, while Fig. 14 shows the mat device 
disassembled from the recorder. The latter figure shows the V mat 
and the provision for it to move vertically, thus controlling the ex- 
posure at the sides of the slit through which light is coming from the 
light-valve. 

Referring now to the recorder table, which is the lower part of the 
unit assembly, all the meters and controls associated with the re- 



314 



W. C. MILLER 



fj. S. M. P. E. 



corder are mounted in a removable panel at the left-hand side of the 
magazine compartment as shown in Fig. 15. These are all conven- 
tional controls with two exceptions. In the first place, as previously 
mentioned, the illumination from the optical system is now checked 
by reference to a photoelectric-cell meter rather than to the con- 
ventional lamp-current meter. The manual illumination adjustment 




VAUVC' IMAGE 



RECORDER OPTCAL SYSTEM SCHEMATIC 



FIG. 13. Recording optical system. 
Shutter operated by solenoid controlled by automatic 
start system provides synchronizing marks at beginning 
and end of take. During take optical path is unob- 
structed. At all other times condition of light-valve and 
light-source is indicated by light cell reading. 

is a grid circuit rheostat controlling the input to the mercury- vapor 
lamp from its current supply outfit. 

Beneath this meter panel and the magazine compartment are 
mounted the noise -reduction unit, a light- valve feedback unit, and the 
filament supply for both (Fig. 11). Access to the controls of the 
noise-reduction unit is obtained by opening the lower door to this 
compartment. Inasmuch as these controls are infrequently used 
it seemed better to cover them with a door than to take the chance 
of their accidently being disturbed by the operator's movements in 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



315 



front of the unit when changing magazines. All the wiring from the 
recorder to the various units in the table runs in metal gutters formed 
in the table. This provides simplicity of wiring and construction, 
neat appearance, and great ease of replacement if modifications later 
become necessary. Connections from the various units in the table 
to the outside are made through a group of terminal blocks which 
appear at the back near the bottom of the table as shown in Fig. 18. 

The power-supply and control for the mercury-vapor lamp are an 
interesting development. 2 The 
control involves both electrical 
power input and air tempera- 
ture. The manual electrical 
control has already been men- 
tioned. It is characteristic of 
the mercury-vapor lamp that 
its illumination value in the 
desired range varies nearly 
directly with its temperature. 
Advantage is taken of this re- 
lation to control the illumina- 
tion by automatic air control 
of the lamp temperature, which 
is provided by a small motor- 
driven blower which sucks air 
past the mercury-vapor lamp 
through a glass tube surround- 
ing the latter and discharges 
through louvers in the back 
panel of the table. The blower 

motor is of the series type, so connected across the lamp circuit 
that as the lamp temperature tends to change, with a consequent 
change in illumination, the motor speed tends to change in inverse 
manner and thereby changes the cooling-air velocity past the lamp 
to offset the change in illumination. In operation equilibrium is es- 
tablished which maintains a high degree of uniformity of lamp 
illumination. Reference to Fig. 16 will show the blower motor 
mounted directly beneath the lower take-up in the table and con- 
nected to the recording machine by a small vertical tube which leads 
up to the mercury- vapor lamp and draws air past the lamp through 
the glass housing already referred to in connection with Fig. 11. 




FIG. 14. Mat device. 



316 



W. C. MILLER 



LF. S. M. P. E. 



Magazines. For a number of years the studio has been operating 
with the conventional types of film magazine. All these have had 
certain disadvantages which it was practicable to eliminate in a new 
special-purpose design. Provision has to be made for the split-film 
technique, which means that any magazine must be capable of being 
reversed when mounted in the upper position. Fig. 17 shows the 




FIG. 15. Recorder unit instrument panel. 



design that has been developed, which seems to be the answer 
most of the requirements. The magazine is made large enough t( 
accommodate very comfortably a 1000-ft roll of film with ample 
finger space around the outside of the film. Part of this space is 
further utilized to provide a roller that guides the film in exact align- 
ment from the light-trap onto the take-up spool. This guide-roller 
has almost completely eliminated rubbing of the roll of film against 
the sides of the magazine, which has always given difficulty in taking 
up in every type of magazine in the past. The light-trap rollers 






May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



317 



themselves are of a conventional type and need no special description. 
The conventional screw-thread method of holding the cover on 
has been eliminated. Instead, a pair of push-button operated spring 
clamps on either side of the cover hold it in place but permit its 
release by a combined pressure of the buttons and slight rotation of 




FIG. 16. Recorder unit; mercury lamp blower and interlock bus 
selector switch. 

the cover. Thus, by pushing these buttons simultaneously and 
rotating the cover a few degrees the latter is released and is free to 
be removed. Replacing the cover involves merely its insertion in 
place and then rotation until the snap-catches lock it in the closed 
position. Not only is the operation simpler and quicker, but it 
completely eliminates the troubles from crossed threads which have 
always been present in the past. 



318 



W. C. MILLER 



tf. S. M. P. E. 



On the cover a brake mechanism is mounted which acts as a gentle 
hold-back or retarding influence when the magazine is in the upper or 
feed position, in order to prevent "galloping" of the roll of film. In 
the lower position the drum housing of this brake appears on the front 
of the magazine and offers a means of checking the operation of the 
take-up, or in the extreme case, permits hand operation of the take-up 
if any failure takes place, as hand operation of the take-up from the 
rear is not easily accomplished. Take-up adjustment is made from 
the front by removing a loose plate which forms the back cover of the 
magazine compartment in the table. 




ROLLER 



FIG. 17. Recorder magazine. 

Reproducer. The reproducer (Figs. 18, 19, and 20), in common 
with the recorder, consists of two compartments in the front, merging 
into one large compartment in the rear, all as one housing. The 
right-hand compartment contains the basic film-drive mechanism 
which has already been discussed in detail. This is identical to the 
recorder except for the modifications to adapt it to the use of 17.5-mm 
film. The left-hand compartment houses the exciter lamp and the 
slit-producing optical assembly. In addition, directly to the rear of 
the optical compartment is the PEC amplifier mounted in such a 
way that the connections from it to the photoelectric cell are short 
and rigid. 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



319 



Means are provided in the film-drive compartment for rewinding 
film directly through the machine without, however, contacting any 
of the sprockets used during the reproduction process. Also, an 
automatic control switch is provided which disconnects the rewind 
motor when the film runs out, or, if desirable, a switch on the control 







FIG. 18. Reproducer unit; front. 



panel can also be operated manually to stop the rewind motor at any 
given point during the rewind process. 

The optical system from lamp to photoelectric cell is unique in its 
design as certain requirements were imposed which are normally not 
found outside of the MGM studio. As is well known, MGM studio 
standard practice is to use 200-mil push-pull variable-density track. 
Proper scanning of this wide track imposes an optical problem that is 
much more severe than in the case of the 100-mil track. In addition, 



320 



W. C. MILLER 



tf. S. M. P. E. 



it becomes necessary at times to change the system rapidly to ac- 
commodate other types of standard track in current use. Such 
changes happen often enough to require that all machines be made 
adaptable for the use of any kind of sound-track. Fig. 21 shows a 
diagram of the optical system and Fig. 22 shows something of the 





FIG. 19. Reproducer unit; front, normal threading. 

physical arrangement of the parts. The lens tube between the 
exciter lamp and the film is of the conventional stereopticon type 
employing a condenser system focused on an objective lens which 
in turn focuses a mechanical slit on the film. The lens design which 
was developed locally gives coverage that is flat within about one db 
over a 215-mil width (Fig. 23). 4J 

For the optical system between the film and the photoelectric jcell, 
which was developed at this studio, one of the requirements that 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



321 



seemed desirable was that the cell should be mounted above the 
drum and in toward the back of the film compartment. This in- 
volved making two or three bends in the optical path, but now that 
the problem has been worked out the effort that was necessary to 
achieve the result seems well justified. Changes from one sound- 





FIG. 20. Reproducer unit; rear. 

ick system to another may be made sufficiently rapidly to satisfy 
le requirements. Two hundred-mil push-pull and 100-mil standard 
track may be reproduced with no adjustment in the optical system, 
such adjustment being required only if 100-mil push-pull track is 
involved. The adjustment is a movement in and out of the slit-tube 
assembly and of the lens-prism combination in back of the film. 
Under any condition imposed by standard types of tracks the images 
on the photoelectric cell plates are nearly as large as the plates them- 



322 



W. C. MILLER 



[J. S. M. P. E. 



selves and are consequently so greatly diffused that any irregularity 
in the surfaces of the plates causes a negligible effect in the re- 
production. 

Normally two reproducing machines will be mounted on a single 
table base. Single units will be provided where required but in the 
usual cases where a number of machines must be mounted together, 
the double-unit form is more economical and easier to install. In 




ELLFSOOHL MRflOR FORMED Br 
SECTKDN OF CYLINDER MOUNTED 
AT ANGLE TO BEAM 






FIG. 21. Reproducer optical system. 

addition, the double-unit mount provides a unique method of han- 
dling the loop problem. Loops are threaded through the regular film 
path, over a roller in the upper right-hand corner of the film compart- 
ment and thence down to the lower compartment of the table, where 
rollers are mounted that will accommodate slightly more than 50 
feet of loop (Fig. 24). Once the loop is threaded the front door of 
the loop compartment is closed and all loose film is completely en- 
closed. This eliminates the conventional open air type of loop at- 
tachment with its dirt and fire hazards. The 50-ft loop is ample to 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



323 



take care of all production needs as in most cases loops are con- 
siderably shorter than this. 

The reproducer magazine construction is particularly unique. 
Conventional designs of magazine covers have always involved large 
doors which stood out in the operating aisle and were always in the 




FIG. 22. Reproducer optical system. 



way or likely to be bumped by the operator, either damaging the 
doors or injuring the operator. These new magazine doors (see 
Figs. 18 to 20) do not project at all in the open position, and when 
closed present a very neat appearance. A toggle device has been 
worked into the design that ensures that the doors remain either in 
the open or the closed position but never in an intermediate position. 
A description of their operation is somewhat complex but it has been 



324 



W. C. MILLER 



[J. S. M. P. E. 



noted that everyone who has used them has at once been very favor- 
ably impressed with their design and operation. 

As in the case of the recorder, all the controls for each of the re- 
producing dummies are mounted in narrow individual panels at 
the left of the machine to which they relate. In the back of the 
table are the filament-supply units for the PEC amplifiers and for 
the exciter lamps. All connections between the reproducing ma- 
chine proper and the apparatus in its table are made directly in 
gutters, while connections to the outside are made through terminal 
blocks as in the case of the recorder. The automatic rewind motors 
are mounted as part of the upper magazines of each machine, and 
operate by the film-controlled automatic switch previously mentioned. 

Current Supply Devices. An interesting innovation has been 



FIG. 23. Scanning illumination. 

introduced in the method of adjusting the exciter-lamp filament 
current. A variable inductance, which has been named an in- 
ductostat (Fig. 20), controlled on the instrument panel, is connected 
in the primary side of the transformer that supplies the filament 
rectifier. Adjustment of this inductance provides smooth current 
control to the filament and eliminates entirely the usual contact 
problems that are encountered with the conventional rheostat. 

All current-supply devices associated with individual units are 
mounted in the tables that form part of the units. These are, for 
example, noise-reduction, PEC amplifier and lamp-filament supplies, 
except for the mercury-vapor lamp supply if required, and voltage 
regulators for the incoming power-supply. These common supply 
devices may be mounted in table sections forming extensions to the 
tables on which the various machines are mounted. They are made 
to the same dimensions and of same construction as the other tables 



May, 1943] RECORDER AND REPRODUCER EQUIPMENT 



325 



so that they fit into the line-up of units merely as extensions. Inside 
of these supply sections, when the covers are removed, is found an 
apparatus grouping much like an abbreviated relay-rack apparatus 
bay. Incoming power leads come to the units through terminal 
blocks and the outputs of the units are distributed, in turn, through 
terminal blocks to busses connecting the individual recorder and 
reproducer tables. 




FIG. 24. Reproducer unit; front, loop threading. 

Throughout the entire design of this new group of equipment, 
operation requirements and ultimate maximum quality of product 
have been the prune factors governing the work. However, the 
project was undertaken with the conviction that the requirements of 
high-quality and improved operation could be met at a cost that 
would be materially lower than anything that had heretofore been 
attained. Consequently, every attention has been given to the cost 



326 W. C. MILLER 

element, with the result that while the installation has not been 
completed and is still in model form, all the estimates that have been 
made show that the ultimate cost will be a very distinct improvement 
over past history in such matters, based upon present and previous 
installations. The studio is particularly happy about this feature 
of the design, since it is being derived, not only without any de- 
gradation of quality but actually with a quality of product equal to 
or superior to anything that has been commercially practicable up 
to the present time. 

REFERENCES 

1 MILLER, W. C. : "Volume Control by the Squeeze Track," J. Soc. Mot. Pict. 
Eng., XV (July, 1930), p. 53. 

2 DUPY, O. L., AND HILLIARD, J. K. : "A Monochromatic Variable-Density 
Recording System," /. Soc. Mot. Pict. Eng., XXXVI (Apr., 1941), p. 366. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

VOLUME XL JUNE, 1943 



CONTENTS 

PAGE 
Illumination in Motion Picture Production 

R. G. LlNDERMAN, C. W. HANDLEY, AND A. RODGERS 333 

The Paramount Transparency Process Projection 
Equipment F. EDOUART 368 

Special Photographic Effects F. M. SERSEN 374 

Washing Photographic Films and Prints in Sea Water 

G. T. EATON AND J. I. CRABTREE 380 

Program of the Fifty-Third Semi-Annual Meeting at 
New York, May 4-6, 1943 392 

Highlights of the Fifty-Third Semi-Annual Meeting 395 

Index of the Journal, Vol. XL (January- June, 1943) 

Author Index 398 

Classified Index 400 



(The Society is not responsible for statements oj authors.) 







JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

SYLVAN HARRIS, EDITOR 
ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
"President: HERBERT GRIFFIN, 

90 Gold Street, New York, N. Y. 
**Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. \ ' 

** Executive Vice-President: LOREN L. RYDER, 
5451 Marathon Street, Hollywood, Calif. 
^Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Avenue, New York, N. Y. 
** Editorial Vice-P resident: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 
* Financial Vice-President: ARTHUR S. DICKINSON, 

28 W. 44th Street, New York, N. Y. 
** Convention Vice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
*Secretary: E. ALLAN WILLIFORD, 

30 E. 42nd Street, New York, N. Y. 
^Treasurer: M. R. BOYER, 

350 Fifth Ave., New York, N. Y. 
Governors 

*H. D. BRADBURY, 411 Fifth Avenue, New York, N. Y. 
*FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*ALFRED N. GOLDSMITH, 580 Fifth Avenue, New York, N. Y. 
*A. M. GUNDELFINGER, 2800 S. Olive St., Burbank, Calif. 
*CHARLES W. HANDLEY, 1960 W. 84th Street, Los Angeles, Calif. 
*EDWARD M. HONAN, 6601 Romaine Street, Hollywood, Calif. 
*JOHN A. MAURER, 117 E. 24th Street, New York, N. Y. 
** WILLIAM A. MUELLER, Burbank, Calif. 

*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
**H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**JOSEPH H. SPRAY, 1277 E. 14th Street, Brooklyn, N. Y. 
**REEVE O. STROCK, 195 Broadway, New York, N. Y. 

*Term expires December 31, 1943. 
**Term expires December 31, 1944. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motion 
Picture Engineers, Inc., 20th and Northampton Sts., Easton, Pa., or Hotel Pennsylvania, New 
York, N. Y. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1943, by the Society of Motion 

Picture Engineers, Inc. 



ILLUMINATION IN MOTION PICTURE PRODUCTION* 



R. G. LINDERMAN,** C. W. HANDLEY,f AND A. RODGERSff 



Summary. Illumination of motion picture sets for black-and-white cinematogra- 
phy involves special techniques for the long, medium, close-up, and follow shots, as 
also the use of booster lights on outdoor sets. Color cinematography requires, in 
addition, special attention to the color quality of the light and the spectral characteris- 
tics of the film. The paper includes a discussion of these requirements and an ex- 
tensive description of modern lighting equipment. 



When early motion pictures were made sunlight and skylight were 
the only sources of illumination. Glass-covered stages were em- 
ployed for protection against the variables of weather. The only 
means of light-control were reflectors to re-direct the sunlight, black 
scrim for diffusion, and opaque mediums to block out undesired rays. 

The need of auxiliary lighting of a uniform controllable character 
made itself evident quite early, and carbon arc lamps, designed for 
other purposes, were adapted to studio use. These were largely 
flame-type flood lamps, which added to the general illumination but 
were not capable of light projection. Later carbon arc searchlights 
designed for projecting high levels of illumination into very restricted 
areas, were introduced. 

In these early days several attempts were made to use incandescent 
lamps, but the restricted color-sensitivity of the film then employed 
and the absence of high-wattage incandescent bulbs doomed these 
trials to failure. 

The introduction of panchromatic film and new high-wattage con- 



* Presented at the 1942 Spring Meeting at Hollywood, Calif. 
** Mole-Richardson Co., Hollywood, Calif. 

t National Carbon Co., Los Angles, Calif. 
ft General Electric Co., Los Angeles, Calif. 

333 



334 



LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 



structions in incandescent bulbs, coinciding with the introduction of 
sound, brought about a major change in motion picture illumination 
practices. 

A desire on the part of cinematographers for accurate light-control 
brought the condenser-type spotlamp, diverging doors, spill rings, 
special reflectors, and finally the Fresnel-type lens. 




FIG. 1. Large indoor set showing lighting arrangements for 
long shot. (Courtesy Radio Pictures) 

Fresnel-type spotlamps, introduced with both arc and incan- 
descent sources, have had wide acceptance. Except for certain 
special effects this type, where available, is often used to the exclusion 
of all others. It furnishes a beam of light which may be varied, by 
focusing, to provide the desired illumination distribution, with beam 
divergences of 8 to 48 degrees. Depending upon the size of the equip- 
ment, it is used widely for flood-lighting, back-lighting, cross-lighting 



June, 1943] 



ILLUMINATION IN MOTION PICTURES 



335 



and modeling. It is ideally suited for use with special control devices 
described elsewhere in this paper. It also facilitates the use of glass 
filters necessary in conjunction with CP bulbs to match sunlight or 
arc light for color. 



BLACK-AND-WHITE PHOTOGRAPHY 



Although the spectral energy distributions of unfiltered carbon 
arc and incandescent units vary widely, lights from these sources are 




FIG. 2. Medium shot. (Courtesy Warner Bros.} 

freely mixed on sets used for black-and-white photography. Usually 
the carbon arc is employed where a directional, penetrating source is 
required to cut through the general illumination of the set, or 
where high levels of illumination are needed on background material, 
including streak light, shadow-producing light, sunlight effects, and 
masculine characterization. 

Incandescent units are used for broad illumination, and where 
smallness and lightness of weight are important, particularly on 
medium-size sets where high light levels are not indicated. On small 
and medium-size sets many cinematographers use incandescent units 
almost to the exclusion of carbon arcs, whereas others mix arcs and 



336 LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 

incandescents freely. On large sets most cinematographers use mixed 
sources. For close-ups the incandescent is usually indicated for soft, 
feminine effects, whereas the arc is often used for masculine char- 
acterization and to produce extreme gradations of illumination. 

In the preliminary arrangement of lighting equipment the chief set 
electrician, under the direction of the director of photography, sets in 
place the floor and overhead units. The director of photography 
establishes the "key-light," which is directional illumination meas- 







FIG. 3. Black-and-white close-up. (Courtesy Paramount 
Pictures) 



ured near the face of the principal character, and then rearranges, 
reduces, or intensifies the illumination falling upon other areas to 
achieve the desired balance. "Balance" is largely an artistic or 
dramatic rather than a strictly technical effect. 

Although illumination meters are in common use by cinematog- 
raphers, the chief set electrician ordinarily does not use them. His 
problem is to arrange the various pieces of equipment, such as lamps, 
diffusers, dimmers, etc., so that the cinematographer may establish 
a "balance" in a minimum of time. The placement of this equip- 
ment depends upon the experience of the chief set electrician, his 



June, 1943] 



ILLUMINATION IN MOTION PICTURES 



337 



knowledge of the desires of the director of photography, and the 
advance conferences that take place before the set is rigged. ' 

The Long Shot. Fig. 1 shows the overhead and part of the floor 
lighting equipment for a black-and-white long shot. The lamps are 
placed high on parallels around the walls of the set, behind doorways 
and windows, on backings, and on the floor in the foreground. 




FIG. 4. Follow shot. (Courtesy Warner Bros.) 

The Medium Shot. When the camera equipment is moved in for 
a medium shot (Fig. 2) the floor-lighting equipment is moved forward 
and some of the overhead lamps are re-directed. Usually no major 
changes are necessary in the location of overhead and back-lighting 
units. 

Th& Close-Up. This shot (Fig. 3) is also accomplished by re- 
arrangement of the front floor-lighting units and the re-direction of 
overhead lighting equipment. 



338 LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 

Follow Shot. On the follow shot (Fig. 4) the camera follows the 
action around the set or even from room to room. The technique of 
lighting for this kind of shot requires very close cooperation between 
the director of photography and the electrical crew. The entire 
area of travel must be illuminated properly, and it is often necessary to 
raise or lower the illumination levels in certain areas during the 
actual shooting. This is accomplished by placing dimmer banks 
in stragetic locations and by cueing the operators (Figs. 5 and 6). 




FIG. 5. Dimmer bank. 

Booster-Lights. On outdoor daylight shots (Fig. 7) lamps are often 
used to illuminate important areas blocked from receiving sunshine 
or skylight. The action is then not limited to areas having sufficient 
natural illumination. 

COLOR PHOTOGRAPHY 

Color photography is more exacting than black-and-white pho- 
tography. The white-flame carbon arc matches the quality require- 
ments of three-color photography. The rotating high-intensity 



I 

June, 1943] 



ILLUMINATION IN MOTION PICTURES 



339 



arcs and incandescent tungsten sources must be filtered to provide 
the required quality. In black-and-white photography variations 
of quality and quantity of illumination result only in differences in 
shades of gray. In color photography, variation in quality will 
change the colors, and low levels of illumination, which in black-and- 
white photography result only in obscuring shadows, will often change 
the appearance of background, costumes, or features. For example, 




FIG. 6. Dimmer bank. 

if a colored velvet gown were improperly illuminated the folds might 
go black, with the result that the costume would appear as a colored 
gown with black stripes. 

For this reason, whereas the illumination meter is used in black- 
and-white photography chiefly to establish the "key-light," in color 
photography it finds wider use in that both shadow and highlight 
levels are usually measured. Much of the equipment arrangements 
technique that applies to black-and-white photography applies also 
to color photography, the major exceptions being that higher levels 



340 



LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 




FIG. 7. Black-and-white booster shot. (Courtesy Warner Bros} 




FIG. 8. Color long shot. 



June, 1943] ILLUMINATION IN MOTION PICTURES 



341 




FIG. 9. Color medium shot. (Courtesy Paramount Pictures] 




FIG. 10. Color close-up. (Courtesy Paramount Pictures') 



342 



LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 




FIG. 11. Color follow shot. (Courtesy Paramount Pictures') 







FIG. 12. Color booster light shot. (Courtesy 20th-century Fox) 



June, 1943] 



ILLUMINATION IN MOTION PICTURES 



343 



are required for color and the quality of the illumination must 
closely approximate average sunlight. 

Inasmuch as the white-flame arc approximates sunlight in quality 
and a greater quantity of illumination is available from a single 
source, the carbon arc is the most generally used source of illumina- 



















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10O 4000 5000 6000 70 
WAVE LENGTH IN ANGSTROM UNITS 



FIG. 13. Solid line: Spectral energy distribution, 8- 
mm-7-mm MP studio carbons at 37 volts, 40 amperes. 
Dotted line: Spectral energy distribution, solar radiation at 
sea level. 



RELATIVE PHOTOGRAPHIC EFFECT 
10 en vj o 

^0 01 Ul 


ULT.-VIOL. 


VIOLET BLUE GREEN YELLOW ORANGE RED 


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500 4000 4500 5000 5500 6000 6500 700 



WAVE LENGTH IN ANGSTROM UNITS 



FIG. 14. Photographic effect of light on film. 



tion for color. The number of incandescent units mixed with carbon 
arcs on a color set depends upon the artistic and dramatic require- 
ments from the viewpoint of the director of photography. Figs. 
8, 9, 10, 11, and 12 show the color long shot, medium shot, close-up, 
follow shot, and booster light shot. 



344 



LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 



MODERN CARBON ARC LIGHTING 



Modern developments in both carbons and in lamps have adopted 
the carbon arc lighting most effectively to the needs of the studio, 




4000 5000 6000 

WAVt LENGTH IN ANGSTROM UNITS 



FIG. 15. Solid line: Spectral energy distribution, 9- 
mm H.I. carbon arc at 49 volts, 70 amperes through 
glass. Dashed line: Same, through glass and Y-l filter. 
Dotted line: Spectral energy distribution, solar radiation at 
sea level. 




4000 5000 6000 

WAV LENGTH IN ANGSTROM UNITS 



FIG. 16. Solid line: Spectral energy distribution, 13.6- 
mm H.I. carbon arc at 63 volts, 115 amperes through 
glass. Dashed line: Same, through glass and Y-l filter. 
Dotted line: Spectral energy distribution, solar radiation at 
sea level. 

particularly for color photography. The radiation through glass 
from the special motion picture studio carbons developed for use in 
broadside lamps resembles sunlight so closely that it can be mixed 
with sunlight on color productions without the use color-correcting 
niters. The solid line in Fig. 13 shows the energy distribution so 



June, 1943] 



ILLUMINATION IN MOTION PICTURES 



345 



obtained from these carbons and, for comparison, the energy dis- 
tribution of solar radiation at corresponding wavelengths. The 
peak of radiant energy at about 3900 Angstroms, commonly known as 
the "cyanogen band" and usually considered characteristic of the 
carbon arc, is suppressed in the radiation from this arc due to the 
selection of a relatively low arc voltage. The solar radiation curve 
is drawn from data recommended by Parry Moon for use as the 
standard solar radiation near sea level. 14 

The photographic effect of a light-source is determined by three 
factors: intensity of radiation from the source, transmission of the 




4000 
WAV LENGTH 



5000 6000 

IN ANGSTROM UNITS 



FIG. 17. Solid line: Spectral energy distribution, 16- 
mm H.I. carbon arc at 81 volts, 150 amperes through 
glass. Dashed line: Same, through glass and Y-l filter. 
Dotted line: Spectral energy distribution, solar radiation at 
sea level. 

camera lens, and the sensitivity of the photographic film. Since 
each of these characteristics varies with color or wavelengths, photo- 
graphic effect is best defined by a curve representing the products 
of these three factors at various wavelengths. The photographic 
effect of the light from the motion picture studio carbons, previously 
mentioned, recorded on panchromatic film* of the type used in the 
studios for negative production, is shown by the curve in Fig. 14. 
Data for this curve were obtained by multiplying values of illumina- 
tion at various wavelengths, as shown in Fig. 13, by corresponding 
values of the transmission of the lens and the sensitivity of the film. 
The vertical scale of this curve is adjusted to a maximum of 100. 



Eastman Plus-JY Type 1231. 



346 



LlNDERMAN, HANDLEY, AND RODGERS fj. S. M. P. E. 






FIG. 17 (A). (Upper) Typical carbon arc high-in- 
tensity rotating element (Lamps Nos. 4, 5, 6, 7, 8, 9). 
(Lower) Two views of M-R Type 40 Duarc broad- 
side carbon arc mechanism (Lamp No. 3). 



June, 1943] 



ILLUMINATION IN MOTION PICTURES 



347 




FIG. 17(5). Lamp No. 1: M-R Type 27 scoop. Lamp No. 2: 
M-R Type 29 broadside. Lamp No. 3 (Front and rear views) : 
M-R Type 40 Duarc broadside. 



348 



LlNDERMAN, HANDLEY, AND RODGERS fj. S. M. P. E. 




June, 1943] ILLUMINATION IN MOTION PICTURES 349 

Note that the photographic effect in the red range differs little from 
that in the blue. 

Radiation from the high-intensity carbon arcs used for studio 
lighting is relatively somewhat stronger in violet and blue com- 
ponents than that from the motion picture studio carbons. How- 
ever, a light straw-colored filter (Y-1Y is sufficient to correct this 
difference and give substantially the same spectral balance and photo- 
graphic effect as obtained from the motion picture studio carbons. 
The solid line in Fig. 15 shows the spectral energy distribution through 
glass from the 9-mm high-intensity carbon arc at 49 volts and 70 
amperes. The dashed curve shows the distribution through glass 
and the Y-l filter. In similar manner, Fig. 16 shows the distribution 
from the 13.6-mm high-intensity carbon arc at 63 volts and 115 
amperes, and Fig. 17 the distribution from the 16-mm high-intensity 
arc at 81 volts and 150 amperes. 

Following are descriptions of several types of carbon arc lamps 
now in general use in motion picture studios. 

CARBON ARC LAMPS 

Figs. 17 (A), (B), and (C) show some of the various types of lamps 
in the following list. 

(1) M-R Type 27 Scoop. -Chromium-plated reflector and Factrolite 
glass diffuser; solenoid controlled. A twin-arc flood source, used for 
overhead illumination of walls, backings, and other areas that can 
not be lighted satisfactorily by spotlamps. Suspended singly or in 
groups. A smooth, general-purpose light-source. . 

(2) M-R Type 29 Broadside. Chromium-plated reflector and 
Factrolite glass diffuser; solenoid controlled. A twin-arc-flood 
source that may be raised, lowered, and tilted, and used as a floor- 
lighting unit for building up front light to the desired exposure level. 

(3) M-R Type 40 Duarc Broadside. Chromium-plated reflector 
and pebbled, sand-blasted pyrex glass diffuser. An improved motor- 
controlled twin-arc flood-lamp that takes the place of both scoop and 
broadside of the older types. 

(4) M-R Type 65 Arc Spoilamp. Eight-inch diameter Fresnel- 
type lens; high-intensity rotating mechanism. Used for front and 
back-lighting, close-up, and medium shots. The intensity is almost 
uniform in the main portion of the beam, tapering off at the edges 
to permit overlapping adjacent beams without producing zone of 



350 LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 

objectionably high intensity. Within its energy capacity this lamp 
may be used for all photographic spot lighting. 

(5) M-R Type 90 Arc Spotlamp. Fourteen-inch diameter Fresnel- 
type lens; high-intensity rotating mechanism. Used for back- 
lighting, sunlight effects through doorways or windows, etc., for key- 
lighting on sets of moderate size, and for general front lighting into 
the rear areas of deep sets. 

(6) M-R Type 170 Arc Spotlamp. Twenty-inch diameter Fresnel- 
type lens; high-intensity rotating mechanism. Used for back, cross, 
and key lighting, and for wide and narrow-angle front and effect 
lighting. This unit has wider use in both black-and-white and color 
photography than any of the other arc units. 

(7) 24-Inch Sun Arc. Twenty-four inch diameter glass mirror; 
high-intensity rotating mechanism. Normally used with the arc 
crater facing the mirror and a clear glass door on the front of the 
lamp-house. Where very sharp shadows are necessary the clear 
glass door may be moved to the position normally occupied by the 
mirror. A metal door is then placed on the open end. A large num- 
ber of these lamps have been converted to use the same optical system 
as the M-R Type 170 lamp. Used for back-lighting, sunlight effects 
through windows and doorways, etc., for key lighting on sets of moder- 
ate size, and for general front lighting into the rear areas of deep sets. 

(8) 36-Inch Sun Arc. Thirty-six inch diameter glass mirror; 
high-intensity rotating mechanism. Similar to the 24-inch Sun Arc 
except as to size. The 24-inch Sun Arc is rapidly being converted 
to the Fresnel type of lens, but due to its great penetrating power, 
the 36-inch Sun Arc is valuable for extremely long throws and retains 
its popularity in its present form. When a large quantity of diffused 
light is required from this unit, a diverging door composed of strips 
of cylindrical lenses replaces the plain glass door. The lamp is 
used where a very great illumination is required, as in back-lighting 
behind a high level of foreground illumination; or where well de- 
fined shadows are required; or where a clearly defined streak of light 
is required through the general illumination; or for producing a 
general illumination of great penetration and high intensity. 

(9) 80-Ampere Rotary Arc Spotlamp. An 8-inch diameter plano- 
convex condenser or 12-inch Fresnel-type lens; high-intensity ro- 
tating mechanism; one of the early high-intensity arc spotlamps. 
This lamp is not suitable as to color in its present form because of the 
spectral energy distribution of the carbon trim. A number of these 



June, 1943] 



ILLUMINATION IN MOTION PICTURES 



351 



lamps have been converted to the use of 11 -mm X 20-inch high- 
intensity motion picture studio positive carbons to make them suitable 
for color photography. They are used for back-lighting on black- 
and-white sets. 



INCANDESCENT LAMPS 



The incandescent lamp is essentially a piece of tungsten wire heated 
to incandescence in a glass bulb filled with an inert gas to retard the 



IVAV LfN&TH IN A/VG ,5 TR OM 




FIG. 18. Spectral energy distribution in the visible 
region from tungsten filaments of equal wattage but dif- 
ferent temperatures. 



evaporation of the tungsten. The radiation gains in quantity and 
becomes whiter with increasing filament temperature. In Fig. 18 
each curve indicates the relative radiant energy throughout the visible 
spectrum emitted by an incandescent lamp filament of a given color- 
temperature. Note the values of the upper and lower curves at the 
wavelength of 4000 Angstrom units, which is near the limit of visible 
light in the violet. The value of the upper curve at this point is 
about ten times that of the lower curve. Compare this with the 
increase at 7000 Angstroms, near the upper limit of visible red. Here 
the upper curve has risen less than three times the value of the lower 



352 



LlNDERMAN, HANDLEY, AND RODGERS |J. S. M. P. E. 



















































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APPROXIMATE RCLAT/OHSHI 

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FIG. 19. Color-temperature y5. efficiency of Mazda C 
lamps. 



OF A Typ/CAL MOTION PtCTUa.e 
PRODUCT/CM FILM. 






BLU\ GREEN. \YLLoWOQANG { 



FIG. 20. Relative sensitivity of photographic film vs. 
wavelength of radiation. 



June, 1943] ILLUMINATION IN MOTION PICTURES 353 

curve. This fact is important in any photochemical process, since 
most photographic materials are more sensitive to radiation in the 
blue-violet. The higher the color-temperature of the filament the 
more photographically effective is the light. 

Fig. 19 shows the increase in efficiency of Mazda C (gas-filled) 
lamps with increasing color-temperature, measured in terms of 
lumens per watt. The total light output of all incandescent lamps 
is measured in lumens, and the data are published in standard lamp 
catalogs and literature. Fig. 19 therefore provides a handy means of 
determining the approximate color-temperature of any lamp by 
dividing the number of lumens by the wattage. This is of particu- 
lar interest to those using other than standard light-sources in 
color photography. 

TABLE I 
Arc Lamps for Set Lighting 

*Degrees Positive Netative 

Lamp Beam Divergences Carbon Carbon 

No. Unit Min Max No. No. 

1 M-R 27 scoop 1 90 90 1 10 

2 M-R 29 broadside 1 90 90 1 10 

3 M-R 40 broadside 90 90 1 16 

4 M-R 65 spotlamp 4 8 44 2 11 

5 M-R 90 spotlamp 3 8 44 5 14 

6 M- R 170 spotlamp 2 8 48 6 15 

7 24-inch sun arc 2 **10 24 6 13 
7 A 24-inch sun arc (converted) 8 48 6 15 

8 36-inch sun arc 2 - 4 10 32 6 13 

9 80-amp rotary spot 2 **8 30 4 12 
9 A 80-amp rotary spot (converted) 8 44 3 12 

* Approximate figures referring to usable photographic light. 

** With Fresnel-type lens divergences are approximately 8 to 44 degrees. 

In photography we are more interested in the photographic 
effectiveness of the light than in its visual effect, and photographic 
effectiveness depends upon the type of film used. Fig. 20 shows the 
curve of relative sensitivity to radiation at various wavelengths in 
the visible spectrum, characteristic of a typical panchromatic motion 
picture production negative film.* By multiplying the sensitivity 
values given by this curve at various wavelengths by the relative 
energy values given by Fig. 18 for the same wavelengths, the family 

* Data given are for Eastman Plus-Z Type 1231. 



354 LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 

of curves shown in Fig. 21 is obtained. Fig. 21 provides a picture of 
the relative photographic effectiveness throughout the visible 
spectrum for light-sources of equal wattage and various color-tem- 
peratures for this particular type of film.* Note that with rising 
color temperatures the values at the blue-violet end of the spectrum 
are increased in greater proportion than those at the red-orange end. 
Fig. 22 illustrates the improvement in photographic effectiveness 
with lamps of equal wattage, by increasing color temperatures, for 
the Panchromatic film in question. 

TABLE II 

Carbons for Set Lighting 

Carbon Arc 

No. Positive Carbons Amperes Volts 

1 8-mm X 12-inch NP MP studio 2 - 6 - 7 - 8 - 9 38-43 35-40 

2 9-mm X 20-inch Hilow projector 5 - 9 65-70 52-54 

3 11-mm X 20-inch HI MP studio 9 90-95 62-65 

4 l / z X 12-inch 80-amp rotary spot 2 - 7 - 8 - 9 75-80 50-55 

5 13.6-mm X 22-inch HI projector 4 - 5 - 9 110-115 54-56 

6 16-mm X 20-inch HI MP studio 2 - 5 -' 7 - 8 - 9 140-150 64-67 

Negative Carbons 

10 8-mm X 12-inch NP MP studio 

11 7-mm X 9-inch cored Suprex negative 

12 3 /s X 9-inch cored 80-amp rotary spot negative 

13 11-mm X 10-inch plain-cored MP studio negative 

14 Vie X SVa-inch MP studio negative 

15 Va X SVa-mch MP studio negative 

16 7-mm X 9-inch NP MP studio negative 

Theoretically, this increase in photographic efficiency of the 
light-source is limited only by the melting point of the tungsten fila- 
ment at about 3655 K. Practically, it is necessary to design for an 
efficiency somewhat below this value, as the life of the lamp becomes 
uneconomically short at the extremely high color- temperatures. 
At present the highest practicable efficiency is obtained with the 
photoflood lamps which operate between 3400K and 3500K. 
Therefore, the practical design of an incandescent lamp for photo- 
graphic purposes involves a compromise between efficiency, life, 
size of bulb, necessary additional equipment, and cost of operation. 

* Note that the curves for incandescent filament light-sources do not extend 
below 4000 Angstroms. They are therefore relative, only to other incandescent 
filament sources or for determining the photographic effectiveness of visible light. 



June, 1943] 



ILLUMINATION IN MOTION PICTURES 



355 



~T-| rr-i 

EFFECT ON THXCJU. Morion 
PICTURE. PRODUCTION FILM OF RADI- 
ATION FROM TuMssTgtj FtuMeNT 

WATTAZE OUT OF DiFFeneNTll 




*-- WAVE LENGTH - ANQSTR.OM UMTS 



FIG. 21. Relative photographic effectiveness 
of light-sources of equal wattage and various 
color-temperatures. 















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FIG. 22. Relative photographic effectiveness w. color- 
temperature. 



356 LlNDERMAN, HANDLEY, AND RODGERS fj. S. M. P. E. 

By designing lamps to operate at high color-temperatures, high 
efficiency and good actinic quality are gained. The bulbs can be 
comparatively small in size, and the equipment can therefore be 
relatively small and easily applied and handled. However, these 
benefits are gained at some sacrifice in the life of the light-source. 
For longer life the efficiency must be lower and the size of bulbs 
and equipment larger, or more equipment must be used for a given 
photographic value. 

As the wattage of a lamp is increased the tungsten filament becomes 
thicker and does not evaporate to the point of failure as quickly, 




FIG. 23. MP and CP lamps listed in Table IV. 



which explains why, at a given color-temperature, the life of higher- 
wattage lamps is considerably longer than for lower-wattage lamps. 

For black-and-white motion picture photography the practice 
has been to design the light-sources for a particular length of life, 
usually between 50 and 100 hours. Such lamps are MP lamps, and 
are listed in Table IV. Since they are designed with respect to life, 
the color- temperatures vary over a range of approximately 400 K. 
This results in high-wattage lamps, which are relatively more efficient 
and produce higher color-temperatures than the lower wattage 
lamps. 

For color photography the major consideration is to have light of 
substantially the same color-quality from all sources. For this pur- 



June, 1943] ILLUMINATION IN MOTION PICTURES 357 

pose, a second group of lamps, designated CP lamps, also shown in 
Table IV, is designed for a particular color- temperature. Here the 
higher-wattage lamps have longer lives than the lower-wattage lamps 
because the heavy filaments do not evaporate as rapidly. Note 
that in the case of the 5-kw and the 10-kw sizes the characteristics 
of the CP and MP lamps are identical. For this reason it has be- 
come possible to design a single lamp in each of these two wattages 
that is correct for both black-and-white and color photography 
when operated at the rated voltage. The MP and CP lamps listed 
in Table IV and illustrated in Fig. 23, form the backbone of modern 
studio lighting practice. They fall logically into four wattage groups, 




FIG. 24. General service lamps used in broads and floodlights. 



with two lamps in each group suitable for a particular size of equip- 
ment to fill a specific need. The 10-kw lamp is a possible exception, 
requiring larger equipment. This standardization of light-sources 
and equipment greatly simplifies the problem of set lighting. 

Most professional color motion picture processes are balanced to a 
color-quality approximating that of average daylight. Special 
color-filters are available for use with the CP lamps to filter out the 
proper proportions at the red-orange end of the spectrum to adapt 
the light to such processes. If lower color- temperature lamps were 
used the filter necessarily would have to absorb greater quantities of 
red and orange light, and the overall efficiency would be very low. 



358 



LlNDERMAN, HANDLEY, AND RODGERS [J. S. M. P. E. 




FIG. 24(4). Lamp No. 10: M-R Type 16 Cinelite. Lamp No. 11: 
Broadside (doubles), M-R Type 20. Lamp No. 12: Broadside (singles). 
Lamp No. 13: M-R Type 45 rifle lamp. Lamp No. 14: Sky light. 
Lamp No. 15: Overhead strip light. 



June, 1943] ILLUMINATION IN MOTION PICTURES 359 

For Technicolor photography, an approved filter, such as the Whiter- 
lite filter, must be used with the CP lamps. 

In many instances high-efficiency bulbs of the shape and appear- 
ance of general service lamps are used in "broads" and floodlights. 
Table IV lists the lamps available for such purposes, and the lamps 
are illustrated in Fig. 24. The daylight blue photofloods may be 
used as supplementary light-sources for color processes balanced to 
daylight. The smaller lamps in this group are often used as "practi- 
cal" lamps, concealed in lighting fixtures and behind objects on the 
set. Small standard projection lamps also are often used in lighting 
fixtures as "practical" lamps. 

Average Life. Although a given type of lamp is designed for a 
particular laboratory life, obviously they will not all burn out at 
exactly the same time, but the majority of them can be expected to 
fail close to the rated time. 

Initial Lumens. All lamps are rated according to their initial light 
output. The output decreases somewhat throughout life due to black- 
ening of the bulb by tungsten evaporated from the filament. In 
gas-filled lamps the majority of the blackening occurs on the glass 
directly above the filament, and is due to currents of gas carrying 
the tungsten particles upward. In the 10-kw and 5-kw lamps, con- 
siderable blackening may occur in time, and for this reason a small 
quantity of granulated tungsten is provided in the bulb. After 
approximately each 10 hours of use, the lamps should be removed 
from the socket and the tungsten powder swirled about in the bulb, 
cleaning off the blackening and restoring the efficiency to nearly the 
original value. This tungsten powder is also provided in the 2-kw 
T-48 or G-48 mogul bipost MP lamps. 

Voltage Rating. In general, the photoflood and movieflood lamps 
are rated at 105-120 volts. The data on wattage, color- temperature, 
light output, and life of these lamps apply to their use at 115 volts. 
The MP lamps are usually supplied in the 120- volt class as this is 
the voltage available in most studios. However, when the supply 
lines to the sets are heavily loaded the voltage is usually closer to 
115 volts. For that reason the CP lamps are ordinarily supplied in 
the 115-volt class as it is extremely important that the color- tempera- 
ture be maintained at 3380K. Also at this voltage the color- 
temperature will match that of the photoflood and movieflood 
lamps. 

A drop of 1 volt below the voltage rating of the lamp will cause a 



360 



LlNDERMAN, HANDLEY, AND RODGERS IJ. S. M. P. E. 




FIG. 24 (B). Studio spotlamps lens types. Lamp No. 
16: M-R Type 414 senior solarspot. Lamp No. 17: B & M 
senior. Lamp No. 18: M-R Type 410 junior solarspot. 
Lamp No. 19: B & M junior. Lamp No. 20: M-R Type 
406 baby solarspot. Lamp No. 21: B & M baby Keg-Lite. 
Lamp No. 22: B & M Dinky Inky. 



June, 1943] ILLUMINATION IN MOTION PICTURES 361 

decrease in color-temperature of approximately 10K, a decrease in 
light output of approximately 3 per cent, and an increase in life of 
approximately 6 to 12 per cent. 

Following are descriptions of several types of incandescent lamps 
now in general use in motion picture studios. 

INCANDESCENT LAMPS 

Figs. 24(^4), (B), and (C) illustrate the various incandescent lamps 
described in the following paragraphs. 

(10) M-R Type 16 Cinelite. A spun aluminum reflector, finished 
inside by wire brushing and chemical treatment, which gives it a 
diffusing characteristic; used where lightness and portability are 
required. 

(11) Broadside (Doubles). Two flood-type reflectors housed in one 
unit, used for floor, side, and overhead lighting. One of the first 
incandescent units made. 

(12) Broadside (Singles). Similar to lamp no. 11, but accommo- 
dating only one bulb. 

(13) M-R Type 45 Rifle Lamp. Stamped metal reflector, chro- 
mium plated with rifled corrugations for diffusion. Used for general 
floor lighting. 

(14) Sky Light. A shallow diffuse reflector about 24 inches in 
diameter. Used below and above sky backings and screens, where 
flat, even light distribution is required. 

(15) Overhead Strip Lamp. A trough-like unit containing sockets 
for five 1000-watt PS52 bulbs. Used to supply fill-in light where it is 
difficult to use a more bulky housing. 

(16) M-R Type 414 Senior Solarspot.A 14-inch diameter Fresnel- 
type lens. An Alzac spherical mirror is used at the rear of the bulb 
to direct the light toward the lens. Used where high- wattage units 
are desirable, for back-lighting, front-lighting, and side-lighting. 

(17) B&M Senior. Similar use to lamp No. 16. 

(18) M-R Type 410 Junior Solarspot.A 10-inch diameter Fresnel- 
type lens. An Alzac spherical mirror is used at the rear of the bulb 
to direct the light toward the lens. Used for back-lighting, front- 
lighting, and modeling within its intensity range. 

(19) B&M Junior. Similar use to lamp No. 18. 

(20) M-R Type 406 Baby Solarspot.A 6-inch diameter Fresnel- 
type lens. An Alzac spherical mirror is used at the rear of the bulb 
to direct the light toward the lens. The small size of this lamp 



362 



LlNDERMAN, HANDLEY, AND RODGERS (J. S. M. P. E. 




June, 1943] ILLUMINATION IN MOTION PICTURES 363 

permits its use in places where the larger lamps can not be accommo- 
dated, particularly where it is necessary to conceal a source of high- 
intensity light. 

(21) B&M Baby Keg-Lite Similar use to Lamp No. 20. 

(22) B&M Dinky Inky. An extremely small Fresnel-type lens 
unit accommodating 100 or 150- watt bulbs. For use where high- 
intensity controllable light is needed at close range from a unit 

TABLE III 

Incandescent Lamps for Set Lighting 

*Degrees Beam 

Lamp Divergences Bulb No. Bulb No. 

No. Unit Min Max **(B & W) Color 

10 M-R type 16 Cinelite 60 60 12 

11 Broadside (doubles) 90 90 11 9 

12 Broadside (singles) 90 90 5 

13 M-R type 45 rifle lamps 60 60 10 or 11 

14 Skylight 180 180 2 2 

15 Overhead strip lamp 11 

16 M-R type 414 senior solarspot 10 44 2 2 

17 B&M senior 10 44 2 2 

18 M-R type 410 junior solarspot 10 44 3 3 

19 B&M junior 10 44 3 3 

20 M-R type 406 baby solarspot 8 40 5-6 5-6 

21 B&M baby Keg-Lite 8 40 5-6 5-6 

22 B&M Dinky Inky 7 or 8 

23 M-R type 226 24-inch sunspot 8 44 2 2 

24 M-R type 360 36-inch sunspot 12 24 1 1 

25 B&M type T-5 or M-R lens type studio 

spotlamp 8 40 2 2 

* Approximate figures referring to usable photographic light. 
** For black-and-white photography. 

which may be hidden behind a pillar, mounted on the camera dolly 
or carried by an assistant. 

(23) M-R Type 226 24-Inch Sunspot A 24-inch diameter glass 
mirror, with a spill ring that allows only projected light to leave the 
lamp. Used for back-lighting large sets, in which case the heads 
are removed from the pedestals and are mounted on parallels or 
platforms built at the top of the set or hung from the stage roof or 
ceiling. 

(24) M-R Type 360 36-Inch Sunspot. A 36-inch diameter glass 
mirror. Used where the highest intensity of projected light is re- 
quired from an incandescent tungsten source. 



364 



LlNDERMAN, HANDLEY, AND RODGERS fj. S. M. P. E. 



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ILLUMINATION IN MOTION PICTURES 



365 



(25) B&M Type T-5 and M-R Lens Type Studio Spotlamp.A 
short-focus Fresnel-type lens in front of the bulb and a small fixed 
spherical mirror behind the bulb project light forward into the field. 
This, in combination with the light projected around the lens from 
the 24-inch reflector, gives an even, intense light. For the large 
mirror, either a 24-inch diameter aplanatic reflector or a 10-inch 
focus glass mirror is used. The aplanatic reflector produces a very 
even field of light. Greater penetrating power for long throws 
may be obtained with the parabolic glass reflector. Used for back- 
lighting, cross-lighting, front-lighting, and effect-lighting. 



TERMS USED IN STUDIO LIGHTING PRACTICE 

The terms applied to the various units of motion picture studio 
lighting equipment are legion and vary from studio to studio, and 
even from month to month. Sometimes a lamp is described by its 
type number alone; or by the rated current, in the case of arc spot- 
lights; or by the kilowatt rating of incandescent units. In some in- 
stances the mirror diameter supplies the name. Below are some 
commonly used terms, the "Lamp Numbers" referring to the pre- 
ceding sections : 



Term 

Broad 

Side arc 

Sixty-five 

Ninety 

One-seventy 

Twenty-four 

Thirty-six 

Eighty 

Rifle 

T-5 



Lamp No. 

2-3-11-12 

2-3 

4 

5 

6 

7 

8 

9 

13 

25 



Term 

Twenty-four Inky 

5KW 

Baby 

Keg 

Junior 

Senior 

Pan or skypan 

Doubles 

10 KW 

Strip 



Lamp No. 

23-25 

23-25 

20-21 

21 

18-19 

16-17 

14 

11 

24 

15 



The following are a few terms used for material and equipment 
associated with the use of studio lamps : 

Silks. Frames equipped with china silk diffusers, hung on the 
fronts of lamps to diffuse the light and reduce the intensity. 

Jellies. Frames equipped with chemically treated gelatin. Used 
for the same purposes as silks. 

Scrim. Black gauze used in various places to reduce intensity and 
diffuse light. 



366 LlNDERMAN, HANDLEY, AND RODGERS fj. S. M. P. E. 

Diverging Doors. Strips of cylindrical glass lenses. Used on 
sun arcs for light diffusion. 

Snotits. Various shapes of black sheet-metal hangers. Used on 
the fronts of lamps to block out undesired light. 

Spill Rings. A series of sheet-metal tubes, used in front of incan- 
descent bulbs in mirror-type lamps to block off angular rays emanat- 
ing from the front surface of the bulb or filament (see photographs of 
lamps 23-24). 

Spot Projector. A unit equipped with a condenser system that 
fits on the front of a type 170 carbon arc lamp in place of the Fresnel- 
type lens; used to produce a sharply defined round spot of light. 

Barn Doors, Gobos, Flags, Cheese Cutters, Niggers, etc. It is often 
desirable to place opaque screens at various points on a set to keep 
all or a part of the light from reaching certain areas or objects. These 
screens are painted dull black and are rectangular, square, or cir- 
cular, as the occasion may require. 

LAMP FILTERS FOR COLOR PHOTOGRAPHY 

Carbon Arc Lamps. Carbon arc lamps 1, 2, 3 are used for Techni- 
color photography without color filters. All types of high-intensity 
rotating arc lamps require a type Y-l straw gelatin filter. 4 

Incandescent Bulb Lamps. Where incandescent bulbs are used on 
Technicolor photography a special blue glass Whiterlite filter is re- 
quired along with a series of CP-type bulbs, which burn at a uniform 
color-temperature of 3380K. U 

REFERENCES 

(All references are to J. Soc. Mot. Pict. Eng. except where noted.} 

1 MOLE, P.: "New Developments in Carbon Arc Lighting," XXII (Jan., 
1934), p. 51. 

2 HANDLEY, C. W. : "Lighting for Technicolor Motion Pictures," XXV 
(Nov., 1935), p. 423. 

3 RICHARDSON, E. C.: "Recent Developments in High-Intensity Arc Spot- 
Lamps for Motion Picture Production," XXVIII (Feb., 1937), p. 207. 

4 HANDLEY, C. W.: "The Advanced Technic of Technicolor Lighting," 
XXIX (Aug., 1937), p. 169. 

6 JOY, D. B., AND DOWNES, A. C. : "Characteristics of High-Intensity 
Arcs," XIV (March, 1930), p. 291. 

6 JOY, D. B., BOWDITCH, F. T., AND DOWNES, A. C.: "A New White-Flame 
Carbon Arc for Photographic Light," XXII (Jan., 1934), p. 58. 

7 BOWDITCH, F. T., AND DOWNES, A. C. : "The Pohotographic Effectiveness of 
Carbon Arc Studio Light-Sources," XXV (Nov., 1935), p. 375. 



June, 1943] ILLUMINATION IN MOTION PICTURES 367 

I 

8 BOWDITCH, F. T., AND DowNES, A. C. i "The Radiant Energy Delivered 
on Motion Picture Sets from Carbon Arc Studio Light-Sources," XXV (Nov., 
1935), p. 383. 

9 BOWDITCH, F. T., AND DOWNES, A. C. : "Spectral Distributions and Color- 
Temperatures of the Radiant Energy from Carbon Arcs Used in the Motion 
Picture Industry," XXX (April, 1938), p. 400. 

10 RICHARDSON, E. C. : "A Wide-Range Studio Spotlamp for Use with 2000- 
Watt Filament Globes," XXVI (Jan., 1936), p. 95. 

11 Report of the Studio Lighting Committee, XXX (March, 1938), p. 294. 

12 Report of the Studio Lighting Committee, XXV (Nov., 1935), p. 432. 

13 FARNHAM, R. E., AND WORSTELL, R. E.: "Color Quality of Light of In- 
candescent Lamps," XXVII(Sept., 1936), p. 260. 

14 MOON, PARRY: "Proposed Standard Solar-Radiation Curves for Engineer 
ing Use," /. Franklin Inst., 230 (1940), p. 583. 



THE PARAMOUNT TRANSPARENCY PROCESS 
PROJECTION EQUIPMENT* 

FARCIOT EDOUART** 



Summary. A brief description of the evolution of the modern transparency proc- 
ess projection equipment, from the single-projector, 12-ft screen set-up twelve years 
ago, to the modern 36-ft screen for black-and-white pictures or the 36-ft screen for 
Technicolor, projecting 126,000 lumens of light from a triple-headed projector casting 
three pictures accurately superimposed upon the screen. 



From an engineering viewpoint the transparency, or projected- 
background process of special photographic effects cinematography 
got off to a most unfortunate start. It was never invented, in the 
strict sense of the word. It was put to practical use from the very 
beginning, and there was no opportunity of engineering it into a 
technological coordination of methods and equipment. 

For a number of years before the present process became a reality, 
many in the industry who had been specializing on what used to be 
called the ''blue-screen process" or complementary-lighting method 
of "composite photography," had been thinking how valuable it 
would be if we could simply project a motion picture upon a trans- 
lucent screen from behind the set and the actors by the ordinary 
black-and-white procedure, and rephotograph the screen, set, and 
actors together, so as to produce the illusion that the projected back- 
ground was as real and as much a part of the scene as the actual 
foreground and actors. Three important factors were lacking: 
(1) we needed a simple, non -mechanical method of accurately syn- 
chronizing the background projector and the foreground camera 
shutters; (2) we needed negative emulsions of sufficient speed and 
sensitivity to enable us to record the back-projected picture; and 
(3) we needed better and faster optics, and light-sources of increased 
power to get a brighter image through our background screens. 

* Presented at the 1942 Spring Meeting at Hollywood, Calif. 
** Paramount Studios, Hollywood, Calif. 
368 



PARAMOUNT PROJECTION EQUIPMENT 369 

Some twelve to fourteen years ago, all these things came in rela- 
tively quick succession. The advent of sound gave us a variety of 
simple electrical hook-ups for interlocking the camera and the pro- 
jector. The newer "super-sensitive" panchromatic emulsions gave 
us the needed film-speed. The projection requirements of the in- 
creasingly large theaters led to improved optics and light-sources, 
and the further projection requirements of the wide-film flurry of 
eleven years ago completed the development. 

We finally had what we needed and wanted; and the first pro- 
duction to utilize the new process effectively was Fox's Just Imagine. 
Individuals in several studios assembled various units together as 
well as they could, and began to make back-projection shots. That 
the results were successful is probably more to the credit of the skilled 
craftsmen who operated the equipment than to any enduring merit 
of the equipment itself. 

Yet the many-fathered idea worked. It worked so well that the 
transparency or back-projection process immediately became a very 
vital adjunct to production. It even then began to eliminate, to a 
very great extent, many long location-trips, with the increased costs 
and hazardous delays that such trips generally involve. It mini- 
mized, for example, the need for hiring a full-size ship and, with 
technicians and cast aboard, cruising expensively up and down the 
seas in search of the correct combination of backgrounds and weather. 
It almost completely eliminated the technical difficulties and not 
infrequent dangers involved in making, by straight-forward methods, 
sound scenes showing our actors riding horses, automobiles, air- 
planes, speedboats, and the like. It afforded better control of sound 
recording and lighting in all these scenes. In a word, it conformed 
ideally to the industry's ideal of getting the best possible picture under 
the most completely controllable conditions, and with a minimum 
of time, expense, and danger. 

No wonder, then, that the industry's use of the process has con- 
stantly increased. In 1930, the last year before the introduction of 
the process, the Paramount process department made 146 composite 
process shots by the earlier blue-screen method. The following year, 
using the projection process, this figure was more than doubled, 
while the cost per scene was considerably reduced. Within two 
years, the number was again doubled, with increased economy and 
greater effectiveness. And every year since, we have had to make 
more and more transparency shots, until now we make between 



370 F. EDOUART [j. S. M. P. E. 

1600 and 2000 set-ups a year, and hardly a picture goes out without 
some of these scenes in them. 

Producers and directors constantly strive for greater scope through 
the use of larger, and still larger, screens. When the process first 
began to be used, a scene inside a closed car with a screen six or eight 
feet wide was something to be happy about. Before long, demand 
forced us to find ways of using screens 12, 15, 18, and 20 feet across, 
not only for black-and-white but for color photography as well. 
When we finally succeeded in using a 24-foot screen, demands im- 
mediately arose for a 36-foot screen. 

From an engineering viewpoint, this was decidedly wrong. Our 
equipment was not engineered for the work, and certainly the various 
components had not been designed to work together as a unit. We 
had to build our own equipment, and would usually take the best 
projector-head we could find and equip it with a camera-type pilot- 
pin movement. Some of us used Bell & Howell movements, some 
used Mitchells, adapting them to the service as well as we could. 

It was the same thing with projection lenses, projector lamp 
houses, electrical control systems, and the rest. Though it was 
carefully and accurately made, the best equipment in any studio was 
only makeshift for the purpose. It was a miracle that the equip- 
ment performed as well as it did; and we were at the end of our 
resources to produce more light and more scope with the elements 
we had at hand. 

The manufacturers of the component units could hardly be blamed 
for not producing the special equipment we so urgently wanted. 
The market was far too small, and the requirements far too indi- 
vidualized to permit even the limited volume production known in 
the manufacture of ordinary professional cameras and projectors. 
One studio might prefer Bell & Howell movements for their projec- 
tors, another the Mitchell-type registration. What one expert 
wanted in a lamp house or lens another might condemn. The 
manufacturer was confused, and could not afford to engineer a 
product of which he might sell but two or three single units. 

Realizing this, a group under the sponsorship of the Academy 
Research Council decided to attempt to bring the industry's process 
specialists and the manufacturers and engineers together, to the end 
that we might at least try to set up industry-wide standards and 
specifications for such equipment, from which the manufacturers 
could conduct the necessary engineering research and build equip- 



June, 1943] PARAMOUNT PROJECTION EQUIPMENT 371 

ment that would stand a chance of suiting the majority of the in- 
dustry's transparency or process-shot requirements. 

It was not an easy task. Personalities, professional suspicions, 
and "trade secrets" were involved. Finally we managed to get to- 
gether most of the industry's leading process-shot specialists, the 
engineers of the firms that manufactured cameras, projectors, lenses, 
arc and incandescent lamp houses, and so on. At first the sessions 
of the committee were unproductive; no one wanted to make the 
first move and nobody wanted to withdraw. 

But finally, after many meetings we set up a complete basic speci- 
fication representing definite requirements; auxiliary specifications, 
which were desirable methods of fulfilling these requirements; and 
accessory specifications, which indicated features that were desirable, 
but not indispensable. The specifications were so much beyond our 
immediate requirements that it seemed almost over optimistic to hope 
that they could ever be completely realized. 

The start of the project was in 1938. The specifications were 
approved in 1939. During 1942 the first complete sets of equipment 
built to these specifications were delivered, assembled, and put 
into service. At the Paramount Studio there are at present four of 
these equipments in operation. Each equipment forms in itself a 
complete unit for conventional single -head transparency projection, 
affording illuminating power and convenience of operation hitherto 
unknown. Any of these "singles" will permit us to make shots, 
either in black-and-white or in color, that would previously have 
demanded the old-style triple-head projection. 

For scenes demanding even greater scope, any three of the new 
units can be combined into an extraordinarily efficient new-type 
triple-head assembly by simply removing them from their single 
bases and mounting them on our new standard triple-head base. 

In this triple-head ensemble three complete projection mechanisms 
are used. The center unit is the key machine, and directly faces the 
screen; the two outer units face inward, perpendicular to the center 
machine, and their images are reflected to the screen by means of 
front-surface mirrors. The three images are accurately super- 
imposed on the screen, and the resulting increase of screen illumina- 
tion is in the neighborhood of 280 per cent. By manipulating the 
intensities of the three light-sources, or the densities of the three 
background prints, a considerable degree of control of intensity of 
the projected superimposed composite image is possible. The 



372 F. EDOUART [J. s. M. P. E. 

superposition of the three images tends also to eliminate the graini- 
ness, which is, of course, further assisted by the use of fine-grain 
film-stocks in making the prints, or plates, as we call them. 

Some idea of the advantages that have been gained through the 
triple-head technique, and the recently increased efficiency of the 
new-type units, may be gained from the following figures. A few 
years ago, when we first had need for powerful process-projection 
equipment for a Technicolor picture, we borrowed what was then 
the most powerful single projection unit in the industry, the very 
fine one owned by Selznick Productions. Using a six-inch //1. 6 
Hugomeyer lens, it projected to the screen 26,000 lumens of light. 

We had already developed our own first triple-head equipment 
an assembly of the best units then available before the present 
Academy specification equipments became available. This enabled 
us to work successfully in black-and-white pictures with //2. 3 lenses 
on a 24-foot screen, producing about 47,000 lumens. 

Today, with the new triple-head equipment, we have worked 
successfully on a 36-foot screen in black-and-white pictures, and on 
a 24-foot screen in Technicolor, with a flux of 126,000 lumens! 

It would seem that this accomplishment would cover all require- 
ments of transparency projection process work. However, so closely 
do the demands for greater and greater dramatic scope keep crowding 
on the heels of technical achievement that it has already proved 
inadequate. In a recent Technicolor production the problem arose 
of using a projected background in some very large-scale sequences 
showing a forest fire. Due to the requirements of story, action, and 
setting, a 24-ft screen-width was not sufficient. We finally used a 
spread of 48 feet of background-screen width! More would have 
been desirable, could it have been obtained. 

This was probably the largest projection process set-up so far 
attempted. We used not one triple-head equipment, but two, pro- 
jecting on adjoining screens each 24 feet wide. For one of them we 
employed our own triple unit, and borrowed the second from RKO. 
With these we achieved our shot most successfully; yet inevitably 
the demands of forthcoming productions are already greater. 

In making these shots, we had the serious problem of operating 
six projection heads, two Technicolor cameras, and the sound re- 
corder, all in synchronism. The foreground set was quite large and 
the projectors were never less than 100 feet, and often 150 feet, from 



June, 1943] PARAMOUNT PROJECTION EQUIPMENT 373 

the screen, making the total distance from the camera to the back 
of the projection equipment nearly 300 feet. 

This emphasizes the extreme precision required in designing equip- 
ment for this service. When a single-frame motion picture image 
8 / 4 X 1 inch in size is magnified to fill screens up to 27 X 36 feet, 
every physical, mechanical, and optical imperfection of the film and 
of the equipment is magnified at the same time. Moreover, this 
enormously magnified picture is at the end of an optical "lever-arm" 
100 feet or more in length, and any irregularity in film registration 
and the like in the original negative or in the positive "plates" 
passing through the projector will be disproportionately enlarged 
on the screen. Irregularities in motion will show up strongly in 
comparison with the steadiness of the actual foreground pieces and 
action. With the foreground steady, and the projected background 
portion of the scene unsteady, all illusion of reality would be lost in 
the composite scene. 

The convenience and precision of operating the new units should 
not be overlooked. The design has been such as to provide, as 
nearly as possible, fool-proof, and in some instances, automatic 
operation. Synchronism of camera and projector, for instance, is 
automatically assured. Focusing is effected by remote control, from 
the camera position. The projector may be panned and tilted with 
the freedom of a camera, and with perfect precision. 

Where hitherto most background projectors have been at least as 
noisy as the average theater projector, and necessarily had to be 
operated only from within a bulky, sound-proof booth, the new units 
have been silenced to a degree comparable to that of a modern, 
blimped studio camera. Taking noise measurements at the usual 
45-degree positions about the projector, at a distance of 6 feet, and 
using a meter with a 40-db ear loudness weighting characteristic, 
and calibrated with respect to the standard reference level of 10~ 16 
watt per sq-cm, the noise level of these new machines is below 34 db. 

These are not mere conveniences in operation. They add very 
measurably to the productive capacity of the machines. With the 
earlier transparency process projectors, with their less convenient 
controls and the greater bulk and complication due to the large 
sound-proof booths, one could not work very fast. The new pro- 
jectors can be worked with the speed and facility of studio cameras. 
When making The Forest Rangers, with two triple-head projectors, 
and simultaneously projecting six plates in Technicolor, the speed 
of production was equal to that of shooting straight shots. 



SPECIAL PHOTOGRAPHIC EFFECTS* 
FRED M. SERSEN** 



Summary. The special photographic effects department is the natural result 
of the difficult problems that develop in motion picture production. Certain stories 
are written in such a manner that it taxes the ingenuity of this department to the ut- 
most to produce the effects required in bringing to the screen the visual record of scenes 
described in scripts. Moreover, the public is becoming more and more critical 
in analyzing the results of trick photography, which necessitates absolute perfection 
in obtaining the effects. 

Economy in the matter of time and finance has spurred the special 
effects branch of the industry to its present high level. Many scenes 
would be impossible of achievement owing to prohibitive costs in set 
construction or the impossibility of photographing them in natural 
settings. 

To have a highly efficient working organization, the department 
must have as a nucleus a competently trained camera crew that 
specializes in this particular work. At their disposal should be a 
thoroughly equipped camera room with cameras, projection printers, 
animation machines, laboratories and trained laboratory men, and a 
cutting room and experienced cutter. 

Working in conjunction with the cameramen are the matte artists. 
These men must not only be fine artists, but must have a knowledge of 
architecture, and the ability to match in paint the most delicate tone 
values in the film. 

The shooting of miniatures, and the scenes and actors that will go 
into composite shots, should be supervised by this department, to give 
it full control over all the component parts of such shots. 

Matte Shots. Matte shots are the most often used form of special 
photographic effects. A scene is photographed on the set and only 
enough background is needed to back up the action. This applies 
particularly to ceilings on large interior sets, tops of buildings for 
street scenes, distant landscapes, and foregrounds. The procedure 

* Presented at the 1942 Spring Meeting at Hollywood, Calif. 
** Twentieth Century-Fox Studios, Hollywood, Calif. 
374 



SPECIAL PHOTOGRAPHIC EFFECTS 375 

is either to matte the shot on the set, or to photograph the scene 
without a matte and then make a dupe, at which time the matte is 
used. This is done by using a painted white surface of such form as to 
allow only that portion of the film to be printed that is to form part 
of the scene. The remainder of the surface is painted black to 
prevent exposure in the part of the scene that is to be filled in by 
painting. The shot is then taken over by a matte shot artist, who, 
in accordance with the design furnished by the art director, paints 
the picture necessary to complete the matted-out portion of the shot. 

When the painting is far enough advanced it is exposed into the 
dupe that was previously made, to determine the exposure. This is 
done by exposing a length of four or five feet of film, which is de- 
veloped immediately and analyzed for exposure, as well as for the 
tone value of the painting, which is corrected either by changing the 
exposure or by changing certain tones in the painting, or both. This 
procedure is repeated until the proper balance between the painting 
and the dupe is attained. 

In shooting a matte shot the camera should be set upon a solid 
foundation and braced to prevent any possibility of vibration. 

Glass Shot. Glass shots were among the first special photographic 
effects but have been largely replaced by matte shots. A glass 
shot is used today only when it is necessary to finish the shot at the 
time it is photographed, or when panning of camera is required. 
When shooting a panning glass shot the camera must be set upon a 
special head, so that the center of the lens is at the pivot of the pan. 

The artist paints the necessary background, which must be matched 
perfectly in tone values for a definite kind of lighting. This makes it 
necessary to photograph glass shots at a certain time of the day to 
match the lights and shadows in the painting, otherwise hurried 
changes are necessary in the painting that are invariably detrimental 
to the quality of the shot. 

Painted Insert. Painted inserts usually embrace theater mar- 
quees, street and building signs, static establishing shots of country- 
sides, etc. These are painted by matte artists on 3 X 4-ft boards 
from designs usually furnished by the art directors, and such scenes 
are fully developed either by the artists or by redesigning enlarged 
photographs of stock shots from the film library, or from stills. 

Composite Shots. A composite shot is a combination of two or 
more separately photographed scenes into one picture. In some in- 
stances ten or twelve exposures are put together in a finished scene. 



376 F. M. SERSEN [J. S. M. P. E. 

This type of shot is used principally to create scenes of large crowds 
of people such as theater audiences, mob scenes in streets, etc., and 
is of great value in saving time on the set and in being able to use the 
same people in various positions, thereby eliminating the necessity 
for hiring a great crowd of extra talent. For example, the interior 
of a theater auditorium is divided into sections, the size of each sec- 
tion being gauged by the number of available talent allowed by the 
budget. The people are moved from section to section until all the 
sections are photographed from the same set-up. If the scene calls 
for simultaneous stage action, the action can be photographed at a 
later date and combined with the final composite. This is one of the 
simpler forms of composite shots. 

An example of a more complicated type of composite occurs in 
The Rains Came. Action called for an earthquake, with portions of 
the ground opening up and portions sinking; people running 
away from the crevasse and being trapped by falling debris 
from buildings tumbling down in the background. The procedure 
for making this kind of shot is briefly as follows : A sketch is care- 
fully made to portray the action of the people and the elements 
involved, keeping constantly in mind the mechanical require- 
ments. After the sketch is completed it is broken down into the 
various sections that will comprise the finished scene: first, the set 
in which the people will be photographed, keeping in mind the num- 
ber of people available in order to determine the number of sections 
that will have to be filmed; second, the miniature of the sinking 
ground and the miniature of the buildings tumbling down. These 
must be figured to the proper scale, each as a perfect unit, so that in 
the finished scene all the parts will fit together like a jig-saw puzzle. 
To accomplish this a complete set of drawings is made, covering 
the set, camera set-ups, proper time to shoot each section, etc. Such 
working out of the details is necessary to eliminate guesswork and to 
assure a smoothly running unit when the scene is photographed. 

It is very important that the action of the elements and of the 
people be accurately coordinated, in order to determine the correct 
footage needed for the scene; this is particularly important when 
animated travelling mattes are to be used. 

Miniatures are then shot to establish coordination with the action of 
the people, or vice versa, and the scene is ready to be put together. 
The scene of earthquake and falling debris was made by using sta- 
tionary mattes for printing certain sections of the scene, and, where 



June, 1943] SPECIAL PHOTOGRAPHIC EFFECTS 377 

necessary, travelling mattes, for combining these sections with the 
other sections. The scene was then brought to completion by paint- 
ing in the sections not covered by sets or miniatures. 

Another kind of composite permits a small set, or a portion of a 
set, by photographing the set from various camera set-ups so that 
the combination of the shots results in a picture of a larger set. For 
instance, a shot calling for a four-story building, showing action at 
the windows, can be made by building a set of only one story and 
photographing it from four different levels. 

Split Screen.- Up to a comparatively short time ago split-screen 
shots were made on the set, but there was always the possibility of a 
slip-up in synchronizing the action. The improved method is to 
photograph the various parts of a scene on separate negatives from 
the same set-up with the same lighting. This makes it possible to 
synchronize and match the component parts more accurately. 

Double Exposure. Ghost effects are typical examples of double 
exposure. They are accomplished by photographing the two com- 
ponents separately, resulting in better photographic balance and syn- 
chronism of action. 

Animation. Animation covers a wide field, such as putting lights 
into night shots of moving objects boats, trains, headlights of 
automobiles, gag shots, bullets shattering windshields of automobiles, 
animated map diagrams, flashing letters and signs, and practically 
everything that can not be done on the set in regular production. 

Travelling Matte. Travelling mattes are primarily useful in 
combining people or moving objects with another background either 
rear or miniature, or painted such as buildings falling upon people 
in earthquakes, forest fires into which are put actors, battle scenes, 
floods in which people are engulfed, and many other composite shots 
where the stationary matte can not be used. 

The object to be photographed is usually shot against a backing 
of high tone with the object itself, viz., a man dressed in white clothes 
would be shot against a dark background or vice versa. 

There are several systems for making travelling mattes, all of 
them intricate, and highly trained technicians are required to com- 
plete such shots successfully. 

Storm Effects. It is often impracticable to use storm effects such 
as rain, snow, fog, dust, lightning, etc., at the time of shooting scenes 
on the set. When such is the case the scenes are photographed 



378 F. M. SERSEN [J. S. M. P. E. 

without the effects, and they are later put in by more suitable 
methods. 

Duped Shots. In exterior shots, owing to the vagaries of weather 
and shooting schedules, it is often impossible to achieve correct 
photographic balance throughout a sequence. This is particularly 
true where dust, fog, and rain are concerned. By duping such shots 
the photographic quality of a scene can be controlled, thereby ob- 
taining a more uniform balance for the entire sequence. 

Miniatures. Miniature scenes are very often necessary to create 
an illustion of reality. To photograph some scenes full size is 
impracticable, often impossible, due to risk of life and prohibitive 
cost. For example, scenes of automobiles falling over cliffs or struck 
by trains, fires, floods, and explosions are only a few instances in 
which the risk would be too great. 

The miniature is one of the most important special photographic 
effects. The factors contributing to success in photographing 
miniatures are scale, perspective, detail, color, lighting, and crank- 
ing speed of the camera. The men assigned to this work are special- 
ists, and require years of training. 

The scale of the set is the starting point, and is determined usually 
by the kind of miniature needed. Whenever possible the set is 
built as large as is practicable and economical. Perspective is im- 
portant to create the proper effect. Due to the fact that miniatures 
are photographed at relatively short distances it is difficult to keep 
the focus sharp from the foreground to distant background. This 
sometimes calls for "forced perspective" in the construction of the 
set. An example of this is the scene from The Rains Came, in which 
the flood waters rush over people running across a bridge. The real 
bridge, with the action of the people, spans Arroyo Seco in Pasadena. 
It is a long bridge, and it would have been impossible to carry it in 
focus throughout its entire length. In the reproduction, therefore, it 
was foreshortened to about one-third its actual length. 

The amount of detail in miniatures is related to the scale, the dis- 
tance of the set from the camera, and the time of shooting the 
scenes, i. e., day or night. Miniatures must be lighted and painted 
so that the illusion of full size is accomplished. An instance is a 
"break-away" miniature of a brick building; all the loose parts are 
to be completely painted and then assembled. 

The last, and probably the most important factor, is the cranking 
speed of the camera. This again depends in a great measure upon 



June, 1943] SPECIAL PHOTOGRAPHIC EFFECTS 379 

the scale. The effect of the mass and weight of falling objects in 
miniatures is achieved by turning the camera at greater than normal 
speed. 

Coordination of all these factors is essential in achieving the final 
result. Action cranked at high speed, finally appearing on the screen 
at normal speed, often happens in a split second. This calls for 
ingeniously rigged controls which are usually manually operated. 

With the advancement in the duping of technicolor film all the fore- 
going effects can be, and are, done in technicolor as effectively as in 
black and white. Two years ago combination shots had to be photo- 
graphed with background projection, which process lacks the scope 
to produce satisfactorily all the special photographic effects de- 
manded in modern picture production. 



WASHING PHOTOGRAPHIC FILMS AND PRINTS 
IN SEA WATER* 



G. T. EATON AND J. I. CRABTREE** 



Summary. The use of sea water for washing photographic materials is practical 
only when a final wash of about 5 minutes in fresh water is used. This final wash 
removes the residual salts from the material and thus prevents (1} rapid fading of 
the image caused by these salts in the presence of hypo, and (2} absorption of moisture 
by the hygroscopic sea salts. 

The removal of hypo is greatly accelerated during washing in sea water as compared 
with fresh water. As a result, it is recommended that films and prints be washed in 
sea water for about one-half of the usually recommended times and finally for about 5 
minutes in fresh water. 

An increase of 20 to 40 F in the temperature of sea water increases the rate of 
washing by 25 to 50 per cent but washing at as low a temperature as 50 F removes 
the hypo more rapidly than at 70 F in fresh water. 

The total time involved in washing in sea water followed by fresh water is somewhat 
less than that required in fresh water alone. 



The permanence of a photographic image is dependent upon many 
factors including (a) the quantity of residual hypo and silver in the 
processed film or print, and (&) the subsequent storage conditions. 
If a photographic film or print is improperly fixed and then incom- 
pletely washed, considerable quantities of silver thiosulf ates and hypo 
may be present. These silver compounds and hypo are reasonably 
stable at the average humidity and temperature of temperate cli- 
mates but, under more severe conditions such as prevail in the tropics, 
the silver compounds tend to decompose, producing silver sulfide 
which appears particularly in the non-image areas as a yellowish 
to yellow-brown stain while the interaction of hypo and the silver 
image produces a yellowish -brown image of silver sulfide. The only 
visible effect of age with some film images is a change in hue to 
bluish-black but the fine-grain film images usually display a more 



* Received February 11, 1943; Communication No. 910 from the Kodak 
Research Laboratories. 

** Eastman Kodak Company, Rochester, N. Y. 
380 



WASHING FILMS AND PRINTS IN SEA WATER 381 

characteristic yellow-brown color. These changes in hue of the silver 
image, with or without the non-image stain, are commonly described 
as "fading." 

In addition to these primary causes of fading, the image may be 
changed in the presence of hypo, when exposed to atmospheres 
containing acidic gases such as sulfur dioxide or nitrogen oxides. 
Hydrogen sulfide, of course, will convert the silver image to silver 
sulfide in the absence of hypo. Fading, however, may occur in the 
absence of hypo or sulfur compounds in the case of film with nitrocellu- 
lose base when exposed to high temperatures. 1 Nitrogen oxides are lib- 
erated and, in the presence of moisture, the resulting nitric acid re- 
acts with the silver image causing fading. 

The quantities of residual silver compounds and hypo in films 
or prints are dependent upon the completeness of fixation of the 
emulsion and the degree of washing. If some silver salts are re- 
tained by the film or print, the hypo can not be completely removed 
since the silver is retained as a silver thiosulfate compound. Thus, 
after complete fixation (in multiple baths, if necessary), the hypo is 
removed by washing and this is most effective when (a) the tempera- 
ture of the water is not below 65 to 75F, (b) the renewal of water 
is adequate at the surface of the material, and (c) when good agitation 
is employed. 

During washing the hypo content decreases with increasing times 
of washing and the propensity to fade is correspondingly decreased. 
This is important from a practical viewpoint because it is possible 
to determine the time of washing required for a given washing 
system in order to leave a certain quantity of residual hypo in the 
material. This quantity is dependent upon whether the film or 
print is intended for commercial or archival purposes. 

The use of sea water for the washing of photographic materials 
has not been widely recommended in the photographic literature. 
K. C. D. Hickman, 2 and J. I. Crabtree and G. E. Matthews 3 sug- 
gested that it could be used but that it was necessary to wash for a 
short time in fresh water before drying. The latter also stated 
further that "even after squeegeeing (film) a considerable quantity 
of the constituent salts remains and the hygroscopic magnesium 
chloride causes 'dampness' and tends to accelerate fading of the 
silver image. ..." 

Sea water contains approximately 3.5 per cent of salts, the pre- 
dominating constituents being sodium chloride (26.5%) and mag- 



382 G. T. EATON AND J. I. CRABTREE [J. S. M. p. E. 

nesium chloride (3.0%). A typical composition based on analysis 
of a sample taken from the Irish Channel 4 is as follows : 

Parts per Thousand 

Sodium chloride 26.43918 

Potassium chloride . 74619 

Magnesium chloride 3 . 15083 

Magnesium bromide . 07052 

Magnesium carbonate Trace 

Magnesium nitrate . 00207 

Calcium sulf ate 1 . 33 1 58 

Calcium carbonate . 04754 

Lithium chloride Trace 

Ammonium chloride . 00044 

Iron carbonate 0.00503 

Silica Trace 



Total 33 . 85946 

As early as 1897, M. P. Mercier 5 recommended a hypo eliminator 
solution consisting of 3 parts iodine, 30 parts salt, and 30 parts 
sodium carbonate in a liter of solution. Sea salt was suggested 
as a substitute for salt. It was claimed that this solution would 
permit complete elimination even when the films or prints were in- 
completely fixed so that neither silver nor hypo remained. 

Sodium chloride, the main constituent of sea water, was recom- 
mended for use as a hypo eliminator (1) by Dr. Bannon in 1888-89 
without detailed instructions 6 and by O. Baysellance 7 who suggested 
that prints should be treated ' 'one-half to one hour in 3 per cent 
sodium chloride and then rinsed three or four times in water." 

WASHING FILMS IN SEA WATER 

In order to show the relative effects of sea water and fresh water 
on the removal of hypo, developed Eastman Verichrome film was 
fixed for 10 minutes in F-5 fixing bath then washed in sea water 
obtained off the Maine Coast and in regular tap water (Hemlock Lake) 
used in Rochester. The washing was accomplished by successive 
changes of 5 minutes in a series of trays with continuous agitation 
of the test film in the water. Small samples of the film were taken 
following each change and after drying were analyzed for hypo 
content by the mercuric chloride test for hypo proposed by Crab tree 
and Ross. 8 The temperatures of the two waters were equal and were 



June, 1943] WASHING FlLMS AND PRINTS IN SEA WATER 



383 



maintained at 70F since different temperatures produce different 
rates of washing. 9 The hypo contents given below in milligrams 
per square-inch indicate the trends in washing. 



Washing 
(Changes) 

1 

2 
3 
4 
5 

6 

7 



Time of 

Washing 

(Min.) 

5 
10 
15 
20 
25 
30 
35 



Hypo Content of Film 

Mg per Sq-In 
Sea Water Fresh Water 



0.01 
0.005 

< 0.005 
Nil 
Nil 
Nil 

Nil 



>0.18 

>0.18 

>0.18 

0.18 

0.12 

0.08 

0.05 



These data which are reproduced in Fig. I (A) show the very 
definite decrease in the washing time required in sea water as com- 
pared with fresh water, and demonstrate that sea water is a much 
more effective hypo eliminator when washing film than fresh water 
but other factors to be discussed later must be considered. 



.020 

go.e 
" 

3 on 
i o 10 

H 008 
" 006, 
04 

fooj 




(A) 




TIME Of WASHING (MINUTES) TIME or WASHING (MINUTES) 

FIG. 1. (A) A comparison of the effect of sea water and fresh water on 
the removal of hypo from Eastman Verichrome film. Washed in successive 
changes of 5 minutes each at 70 F. 

(B) A comparison of the effect of sea water and fresh water on the removal 
of hypo from photographic paper. Eastman Azo F-3 (double weight) washed 
in successive changes of 5 minutes each at 70 F. 

WASHING PAPER PRINTS IN SEA WATER 

Similar experiments were made with processed double-weight 
Azo glossy paper. Samples of prints fixed 10 minutes in the F-5 
fixing bath were washed for the times indicated below, dried, and 
then analyzed by the following silver nitrate test. A small piece 
from each print was immersed in acidified silver nitrate solution 



384 G. T. EATON AND J. I. CRABTREE [j. s. M. p. E. 

(1 %) for 5 minutes, then treated in 5 per cent sodium chloride 
solution for 5 minutes followed by bathing in 5 per cent hypo in 2 
per cent sulfite solution, and finally washed. The transmission 
density of the silver sulfide stain was determined and the correspond- 
ing hypo content obtained from a standard curve. 9 The results 
obtained have been qualitatively confirmed by means of the mercuric 
chloride test. Even though the method was not quantitative, the 
order of magnitude of the quantities of the residual hypo was con- 
firmed. 

Hypo Content of Paper (Azo) 
Time of Washing (Mg per Sq-In) 

(Min) Sea Water Fresh Water 

2 >0.320* >.0.320* 

5 0.200 > 0.320 

7 0.130 > 0.320 

10 0.076 > 0.320 

12 0.058 0.265 

15 0.042 0.212 

25 0.009 0.131 

40 0.006 0.100 

50 . Nil 0.079 

* The Capstaff-Purdy densitometer used in this work reads only a density of 
3.0 and consequently 0.320 mg per sq-in of hypo was the greatest amount that 
could be determined in a double weight print by this method. 

These data illustrated in Fig. l(B) show that sea water is a more 
effective hypo eliminator for prints than fresh water. It is 
interesting to note that extended washing times of several hours in 
running fresh water reduced the residual hypo content of double 
weight prints to an average low value of 0.07 mg per sq-in whereas 
sea water, in these tests, removed the hypo completely in 50 minutes. 
However, for permanency it is then necessary to remove the sea 
water from the prints. 

PERMANENCE OF FILM AND PAPER IMAGES 

Permanency as measured in terms of the tendency of film and 
print samples to fade was determined by storage of the samples over 
water in a sealed all-glass container kept at a temperature of 110F. 
It is believed that this accelerated fading test provides a good in- 
dication of the probable fading tendency of a print or film when 
kept under adverse conditions of temperature and humidity. Al- 
though the relationship between accelerated fading tests and normal 



June, 1943 ] WASHING FlLMS AND PRINTS IN SEA WATER 385 

storage conditions has not been precisely determined, negative and 
positive motion picture films stored at Kodak Park 10 for at least 
ten years at 55F and 70 per cent relative humidity and which con- 
tained quantities of hypo of the order of that in present day com- 
mercially processed films, have not shown signs of visible fading. 
A period of one day in the accelerated test would therefore appear 
to be equivalent to a period not less than ten years at a temperature 
of 55F and 70 per cent relative humidity. The data from similar 
keeping tests with prints are not available. 

Under the conditions of the accelerated fading test images on 
Verichrome film did not fade. In general, high-speed negative films 
and types similar to Verichrome do not fade under these conditions 
in the usual sense of the word but, in the presence of quite large 
quantities of residual hypo the hue of the image may change toward 
a bluish or purplish tone. On the other hand, fine-grain film images 
may fade quite rapidly displaying the familiar yellowish-brown 
sulfide tone. 

Experiments made with Eastman Motion Picture Fine-Grain 
Films (1) Duplicating Positive, Type 1365, (2) Fine-Grain Release 
Positive, Type 1302, and (3) Sound Recording, indicated the same 
effect of sea water on hypo removal as obtained with Verichrome 
film. When samples of these washed films were stored under ac- 
celerated fading conditions those images washed in sea water and 
containing as little hypo as 0.01 mg per sq-in were reduced slightly 
in the lowest densities. On the other hand, samples washed in fresh 
water and containing 0.01 mg per sq-in showed no visible change. 
Quantities of hypo from 0.03 to 0.10 mg per sq-in were necessary 
to cause fading of these fine-grain images when washed in fresh 
water. 

Since images washed in sea water f ollowed by fresh water may con- 
tain hypo and sea salt in various ratios, it is necessary to consider 
several possible conditions as follows : 



(a) High hypo no salt 

(&) Low hypo no salt 

(c) High hypo high salt 

(d) Low hypo high salt 

(e) No hypo high salt 

(/) High hypo , low salt 

(g) Low hypo low salt 

(h) No hypo low salt 



386 



G. T. EATON AND J. I. CRABTREE fj. s. M. p. E. 



When prints were washed in fresh water (Hemlock Lake) for in- 
creasing times the hypo content decreased accordingly thus pioviding 
the conditions given in (a) and (b). During storage under ac- 
celerated fading conditions the images on these prints tended to fade 
to a degree roughly proportional to the residual hypo content, that is, 
at low hypo contents the degree of fading was less then at higher 
hypo contents. 

However, if the prints were washed in sea water they always con- 
tained a large quantity of residual sea salts whether the hypo con- 
tent was low or high. Prints washed under these conditions (c) 




RESIDUAL HYPO CONTENTS IN AZO PRINTS (MILLIGRAMS PER SQ INCH) 

FIG. 2. Schematic drawing to show relative degree of 
fading of a print image after washing in sea water and 
fresh water. 



and (d) exhibited very different reactions to the accelerated fading 
conditions. When the hypo content was between zero and 
0.10 mg per sq-in the degree of fading was much greater at hypo 
contents of the order of 0.01 mg per sq-in than was ever obtained after 
washing in fresh water but the tendency to fade decreased as the 
hypo content approached 0.10 mg per sq-in. At residual hypo con- 
tents greater than approximately 0.10 mg per sq-in the degree of 
fading was similar to that with prints washed in fresh water and 
containing this quantity of residual hypo. Low hypo contents 
are therefore particularly harmful in the presence of sea salts. These 
fading results are schematically illustrated in the curves in Fig. 2. 



June, 1943 ] WASHING FILMS AND PRINTS IN SEA WATER 387 

It is also of interest to ascertain the concentration of chlorides 
in water above which these peculiar fading effects are likely to occur. 
The data from tests made with sodium chloride solutions varying 
in concentration from 0.10 to 3.0 per cent showed that bathing in 
solutions above 0.5 per cent produced fading similar to that obtained 
after washing in sea water. 

When the conditions in (e) prevailed, that is, when all the hypo 
was removed by use of the hydrogen peroxide-ammonia hypo elimi- 
nator (Kodak HE-1) and only the residual salts from sea water re- 
mained, the image became slightly purplish under the accelerated 
fading conditions but no visual decrease in the density occurred. 

As suggested above and described subsequently, if the residual 
sea salts are removed by washing in fresh water for about 5 minutes 
(/ and g) the print images fade in the same manner as described 
under (a) and (b) , that is, within the suggested time for a final fresh 
water wash the residual sea salts are sufficiently reduced in quantity 
that any salt remaining has no effect upon the normal fading of a 
print washed in fresh water. If all the hypo is removed and the 
residual salt reduced to a negligible quantity (h) no fading occurred. 

The resistance of coarse grain paper images to fading was much 
greater (approximately twelve times) than that of the fine-grain 
paper images as indicated by the longer time required in the storage 
apparatus to initiate the fading reaction. 

From the fading data described, it is apparent that sea water 
residues left in prints are likely to impair the stability of the silver 
image and that they can cause deterioration of the image under 
storage conditions considerably less severe than are usually deemed 
necessary. 

WASHING IN SEA WATER ALONE IS IMPRACTICAL 

Washing in sea water is impractical for other reasons than the 
increased susceptibility to fading under adverse storage conditions, 
namely: (1) the magnesium chloride constituent of the residual salts 
is hygroscopic and thus tends to produce "sticky" films and prints, 
and (2) while prints washed in sea water can be ferrotyped without 
any visible change in the image, the ferrotyping surface of a metal 
drum or sheet may be corroded by the residual sea salts. 

DISCUSSION 

The experimental data have indicated two important differences 
between washing with fresh water and sea water, namely: (1) hypo 



388 G. T. EATON AND J. I. CRABTREE [j. s. M. P. E. 

is more rapidly removed during washing in sea water, and (2) films 
or prints washed in sea water fade more rapidly when they contain 
very small quantities of residual hypo than they do with larger 
quantities which is opposite to the effect when films or prints are 
washed in fresh water. 

(1) When the gelatin layers of films and prints are immersed in an 
aqueous solution, as in development and fixation, the gelatin becomes 
hydrated, that is, water is absorbed. 

During washing in fresh water the retained hypo slowly diffuses 
from the gelatin but during washing in sea water or salt solution 
(3 per cent), the gelatin tends to become dehydrated and the hypo 
washes from the gelatin more rapidly than in fresh water. 

In the case of paper fibers in the paper base, there is probably a 
similar effect on the fiber membrane tending to dehydrate this and 
expel both water and thiosulfate which may have been held by 
selective adsorption. 11 

(2) Under conditions of high humidity and temperature or under 
tropical conditions, some of the silver of the photographic image is 
oxidized to silver ion. In the presence of hypo the silver ion reacts 
with the hypo to produce yellowish silver sulfide but when sea salts 
are also present, the silver ion reacts to form silver chloride. 

When no 'residual hypo is present, a very small quantity of silver 
chloride is formed which is changed in color by exposure to light. 
The change in the surface condition of the silver image produces a 
change in the reflection characteristics and the image assumes a 
purplish hue. 

In the presence of hypo and sea salts the silver ion probably forms 
a complex silver thiosulfate compound which is more stable as the 
residual hypo content increases. Thus, with very small quantities 
of hypo present the relatively unstable silver compound decomposes 
to produce silver sulfide but with greater quantities of hypo the 
relatively stable compound formed .does not decompose. 12 There- 
fore, in the presence of sea salts or chlorides, the silver image is very 
susceptible to conversion to sulfide when only traces or very small 
quantities of hypo are present. When no sea salts are present, the 
silver sulfide produced is roughly proportional to the residual hypo 
content. 9 

PRACTICAL USE OF SEA WATER FOR WASHING 

After washing a film or print in sea water, if the residual salts could 
be successfully removed, then for a given time of washing the hypo 



June, 1943 ] WASHING FlLMS AND PRINTS IN SEA WATER 389 

content would be much less than following washing in fresh water 
for the same time and the image would therefore be less susceptible 
to fading than is normally the case. 

Accordingly, experiments were made to determine if the quantity 
of residual sea salts could be sufficiently reduced by washing in fresh 
water to insure, at least, normal permanence of the print. One 
series of prints was washed by immersion in equal volumes of fresh 
water for 2, 5, and 8 minutes. A second series of prints was washed 
in successive equal volumes of fresh water for total times of 2, 5, and 
8 minutes. The quantity of chlorides, which are the main constituent 
of sea salts, removed during washing was then determined by titration 
with standard silver nitrate solution after any thiosulfate present 
in the solutions was oxidized to sulfate. 

The total quantity of chlorides removed was found to be es- 
sentially constant for washing times in excess of 2 minutes and 
it was found that bathing with agitation for 2 minutes in fresh 
water in the proportion of 1 oz per 6 sq-in of double weight paper 
was sufficient to 'remove the readily diffusible chloride content. 

The washed prints were then stored under accelerated fading 
conditions to determine if the quantity of salts remaining was suffi- 
cient to adversely affect the keeping properties of the print. None 
of the prints faded which indicated that a final wash of 2 minutes 
in fresh water was sufficient to reduce the residual sea salts to a safe 
quantity. 

The removal of the residual salts may also be accomplished by the 
use of running water for 2 minutes provided adequate agitation is 
employed. 

The effect of temperature of the sea water on the rate of removal 
of hypo is quite similar to the effect with fresh water. 9 The following 
data indicate the effect of increasing the temperature from 50 to 
90F. 

Hypo Content 
Time of Washing (Mg per Sq-In) 

(Min) 50F 70F 90F 

5 0.234 0.180 0.101 

10 0.122 0.076 0.028 

However, at 50F the degree of washing is considerably greater 
than with fresh water at 70 F so that the use of sea water is advanta- 
geous even at low temperatures. 

A consideration of the washing times given previously for hypo 



390 G. T. EATON AND J. I. CRABTREE |J. s. M. P. E. 

removal with sea water and fresh water shows that considerable 
time may be saved in the washing process even when a final wash 
in fresh water is used. The use of this final wash in fresh water is 
imperative and, if omitted, obviates any other advantages gained 
by washing in sea water. 

It is recommended that two changes of 2 minutes each in fresh 
water be used or 5 minutes in running fresh water to remove the resid- 
ual sea salts. 

The following summary indicates the relative times of washing 
by changes required to reduce the hypo content to given values 
by washing in sea water as compared with fresh water. 



Time of Washing in Sea 
Water Followed by Fresh 

Time of Water (2 Changes) 

Washing in Time in Time in Fresh 

Hypo Content Fresh Water Sea Water Water Total Time 

Material (Mg per Sq-In) (Min) (Min) (Min) (Min) 

Eastman 0.20 15 6 4 10 

Azo F-3 0.10 40 9 4 13 

Paper 0.05 60 12 4 16 

Eastman 0.10 25 <5 4 <9 

Verichrome 0.05 35 <5 4 <9 

Film 0.01 35 5 4 9 

0.005 35 10 4 14 



It is apparent from these data that time can be saved by washing 
in sea water or a solution of sea salt or sodium chloride provided 
the residual salts are then removed in fresh water. 

Fresh water supplies which might contain as much as 500 parts 
per million of chloride ion (0.08 per cent sodium chloride) will usually 
not be harmful because this quantity is less than one-sixth the con- 
centration of that previously shown to be necessary to influence 
the normal course of fading produced by increasing concentrations 
of hypo (Fig. 2). 

In view of these and similar data, it is considered that a safe 
and economical procedure would be to wash in sea water for one- 
half of the usually suggested washing time for a given material 
and then wash in fresh water for about 5 minutes either in running 
water or two successive changes. 

Acknowledgment. The authors are indebted to Messrs. C. E. Ives 
and L. E. Muehler for valuable suggestions. 



June, 1943] WASHING FILMS AND PRINTS IN SEA WATER 391 

REFERENCES 

1 HILL, J. R., AND WEBER, C. G.: "Stability of Motion Picture Films as 
Determined by Accelerated Aging," Research Paper RP 950, National Bureau of 
Standards (Dec., 1936). 

2 HICKMAN, K. C. D.: "Washing Motion Picture Film," Trans. Soc. Mot. 
Pict. Eng., No. 23 (1925), p. 73. 

3 CRABTREE, J. I., AND MATTHEWS, G. E.: "Photographic Chemicals and 
Solutions," Amer. Phot. Pub. Co., Boston, Mass. (1939), p. 112. 

4 Van Nostrand's "Chemical Annual for 1926," p. 645. 

5 MERCIER, M. P.: "Sel iode eliminateur rapide des hyposulfites" (lodated 
Salt, Rapid Eliminator of Hypo), Bull. soc. Franc. Phot., 30 (1897), p. 296. 

6 Editorial, Amer. Phot., 19 (1889), p. 38. 

7 BAYSELLANCE, O.: Phot. Rev., 12 (1903), p. 32. 

8 CRABTREE, J. I., AND Ross, J. F. : "A Method of Testing for the Presence of 
Sodium Thiosulfate in Motion Picture Films," /. Soc. Mot. Pict. Eng., XIV 
(April, 1930), p. 419. 

9 CRABTREE, J. I., EATON, G. T., AND MUEHLER, L. E.: "The Elimination of 
Hypo from Photographic Images," /. Phot. Soc. Amer., VI (1940), p. 8. 

10 CRABTREE, J. I., AND IVES, C. E.: "The Storage of Valuable Motion Picture 
Film," /. Soc. Mot. Pict. Eng., XV (Sept., 1930), p. 289, 

11 SHEPPARD, S. E.: "The Removal of Free Acid from Nitrocellulose with 
Special Reference to the Use of Saline Leaches," /. Ind. Eng. Chem., 13 (1921), 
p. 1017. 

12 BASSETT, H., AND LEMON, J. T.: "Sodium Thiosulfate-Silver Thiosulfate 
System," /. Chem. Soc., Part II (1933), p. 1423. Cf. BAINES, H.: "The Chem- 
istry of Fixation," Phot. J., 69 (1929), p. 314. 



PROGRAM OF THE FIFTY-THIRD SEMI-ANNUAL MEETING* 

HOTEL PENNSYLVANIA, NEW YORK, N. Y., MAY 4-6, 1943 

Tuesday, May 4th 

10:00 a.m. Business and Technical Session. 

Opening of the Fifty-Third Semi- Annual Meeting; Donald E. 

Hyndman, Engineering Vice-President. 

Report of the Convention Vice-President ; W. C. Kunzmann. 
Report of the Financial Vice-President; Arthur S. Dickinson. 
Report of the Engineering Vice-President; Donald E. Hyndman. 
"Developments in the Use of Motion Pictures by the Navy;" William 

Exton, Jr., Lt. U.S.N.R., Bureau of Navigation, Navy Depart- 
ment, Washington, D. C. 
"The Production of Training Films by the U. S. Navy;" Training 

Film Section, Photographic Division, Bureau of Aeronautics, 

Navy Department, Washington, D. C. 
"Fast Motion Analysis as an Aid to Organized Invention;" E. M. 

Watson, Capt., Air Corps, Wright Field, Dayton, Ohio. 
"A Note on the Projection Life of Film;" D. R. White and C. de 

Moos, Du Pont Film Mfg. Corp., Parlin, N. J. 

12:30 p.m. Informal Get-Together Luncheon of the Society. 

Speaker: Mr. Edward Kuykendall, President of Motion Picture 
Theater Owners of America, Inc. 

2 : 00 p.m. Exhibitors' Session Joint Meeting with the Motion Picture Theater 
Owners of America, Edward Kuykendall, President. 

"Motion Picture Standards in War Time;" Donald E. Hyndman, 
Engineering Vice-President. 

"Handling Crowds in Emergencies;" Dr. Walter Cutter, Center for 
Safety Education, New York University, New York, N. Y. 

Invited Speakers: 

Terry Ramsaye, Editor, Motion Picture Herald, New York, N. Y. 

William C. Formby, Editor, Boxoffice, New York, N. Y. 
Report of the Sub-Committee on Theater Protection, of the Theater 

Engineering Committee; Henry Anderson, Sub-Chairman. 

8: 00 p.m. Museum of Modem Art Film Library; E. F. Kerns (Technical 
Director, Film Library) , Chairman. 

* As actually followed in the sessions. 
392 



PROGRAM OF SEMI- ANNUAL MEETING 393 

"The Work of the Film Library in War Time;" Iris Barry, Curator 
of the Film Library. The lecture was followed by a showing of a 
compilation of films of current historic interest, from the Archives 
of the Film Library. 

Wednesday, May 5th 

10: 00 a.m. Technical Session. 

Report of the Committee on Cinematography; John W. Boyle, 
Chairman. 

Report of the Committee on Non-Theatrical Equipment; John A. 
Maurer, Chairman. 

"Some Suggested Standards for Direct 16-Mm. Production;" 
Lloyd Thompson, The Calvin Company, Kansas City, Mo. 

"Some Notes on the Application of Fine-Grain Film to 16-Mm. 
Motion Pictures;" William H. Offenhauser, Jr., Precision Labora- 
tories, New York, N. Y. 

"Character of Waves Produced by Explosions;" E. W. Kellogg, 
RCA Manufacturing Co., Indianapolis, Ind. 

2 : 00 p.m. Technical Session. 

"Wartime Cataloguing of Films;" John G. Bradley, The National 

Archives, Washington, D. C. 
"Film Incunabula in the Library of Congress;" Howard L. Wallis, 

Library of Congress, Washington, D. C. 
"Resurrection of Early Motion Picture Paper Prints;" Carl L. 

Gregory, The National Archives, Washington, D. C. 
"Conservation of Photographic Chemicals;" Allan Haines, Pathe 

Laboratories, Inc., Los Angeles, Calif. 
"A Compact Production Unit for Specialized Films;" O. W. Hun- 

gerford, Washington, D. C. 

8 : 00 p.m. Fifty-Third Semi-Annual Dinner Dance of the Society of Motion 
Picture Engineers. 

Thursday, May 6th- 

10:00 a.m. Technical Session. 

"Resistance of Glass to Thermal Shock;" Charles D. Oughton, 

Bausch & Lomb Optical Company, Rochester, N. Y. 
"The Optics of Motion Picture Projection;" John A. Maurer and 

A. Offner, J. A. Maurer, Inc., New York, N. Y. 
"Army Air Forces Training Film;" Col. Lawrence Carr, Training 

Aids Division, Army Air Forces, Washington, D. C. 
"The Operations of Army Air Force Combat Camera Units in the 

Theaters of War;" Ralph Jester, Major, Air Corps Headquarters, 

Army Air Forces, Washington, D. C. 
"Some Factors Affecting Resolution in 35-Mm. Film;" Michael 

Bruno, Capt., U. S. Army Map Service, Washington, D. C. 



394 PROGRAM OF SEMI- ANNUAL MEETING 

2 : 00 p.m. Symposium on the Training Film Activities of the U. S. Army, pre- 
pared by members of the U. S. Army Signal Corps, Army Service 

Forces. 
"General Description of the Motion Picture Activities of the U. S. 

Army Signal Corps;" Capt. H. T. Darracott, U. S. Army Pictorial 

Service, Washington, D. C. 
"The U. S. Signal Corps Photographic Center at Astoria, L. I.;" 

Col. M. E. Gillette, U. S. Army Signal Corps Photographic 

Center, Astoria, Long Island, N. Y. 
"Training Film Production Problems;" Lt. Col. Robert P. Presnel, 

U. S. Army Signal Corps Photographic Center, Astoria, Long 

Island, N. Y. 
"Objectives and Uses of the War Department Service Film;" Lt. Col. 

Emanuel Cohen, U. S. Army Signal Corps Photographic Center, 

Astoria, Long Island, N. Y. 
"Animation in Training Film Production;" Major Ellis Smith, 

U. S. Army Signal Corps Photographic Center, Astoria, Long 

Island, N. Y. 
"Sound Recording Equipment Used at the U. S. Army Signal Corps 

Photographic Center;" Major G. C. Misener, U. S. Army Signal 

Corps Photographic Center, Astoria, Long Island, N. Y. 
"Field Camera Problems;" Capt. Ray L. Ramsey, U. S. Army 

Corps Photographic Center, Astoria, Long Island, N. Y. 
"Multiple Film Scene Selector;" Capt. Harry W. Leasim, U. S. 

Army Pictorial Service, Washington, D. C. 
"Training Film Distribution;" Lt. James D. Finn, U. S. Army 

Pictorial Service, Washington, D. C. 
"Training Film Utilization;" Boyd T. Wolff, Washington, D. C. 

8 : 00 p.m. Lecture. 

"Visual Processes and Color Photography;" Ralph M. Evans, 
Eastman Kodak Company, Rochester, N. Y. The lecture was 
illustrated by more than one hundred lantern slides and prints. 



HIGHLIGHTS OF THE FIFTY-THIRD SEMI-ANNUAL MEETING 



HOTEL PENNSYLVANIA, NEW YORK, MAY 4-6, 1943 

Perhaps the most outstanding feature of the Fifty-Third Semi- Annual Meeting, 
recently concluded at the Hotel Pennsylvania, New York, was the extent to 
which the various services of the Government were represented. Of the forty 
technical presentations on the program, twenty were by members of the U. S. 
Army, the U. S. Navy, the National Archives, and the Library of Congress. The 
Society is greatly gratified at the interest shown in these Meetings by the branches 
of the Government, and is pleased that the various Services are making use of 
the technical facilities that the Society affords. 

Another important feature of the Meeting, and not less important, was the 
joint session held with the Motion Picture Theater Owners of America. The 
Society has long endeavored to expand its activities in the field of theater opera- 
tion and to make its facilities available to theater managers and operators, and 
this joint meeting provided another important step in that direction. 

Approximately two hundred persons attended the various sessions held during 
the three-day conclave, and despite that fact that so many of the members and 
others interested in the Society find it difficult to get away from their wartime 
activities, the individual sessions were extremely well attended. Furthermore, 
despite the great secrecy attending many of the motion picture and associated 
development during these days of war, there was considerable of technologic 
interest in the presentations, and much spirited discussion of the papers was 
aroused. 

The Meeting convened on the morning of Tuesday, May 4th, with a brief wel- 
come by Donald E. Hyndman, Engineering V ice-President, followed by the reports 
of the Convention Vice-President, William C. Kunzmann, and the Financial 
V ice-President, Arthur S. Dickinson. Two papers by members of the Navy, Lt. 
William Exton, Jr., of the Bureau of Navigation, and Lt. Orville C. Goldner, of 
the Bureau of Aeronautics, described the uses and production of training and 
other films by the U. S. Navy. These were followed by the interesting paper by 
Capt. E. M. Watson, of the Air Corps, on the uses of fast motion pictures in 
analyzing and developing mechanisms of importance in ordnance and other 
activities. 

One hundred and sixty persons were present at the Informal Get-Together 
Luncheon held at noon of the same day. The principal speaker was Mr. Edward 
Kuykendall, president of Motion Picture Theater Owners of America, who dis- 
cussed briefly some of the problems attending the operation of motion picture 
theaters during the present war time. 

The afternoon of Tuesday, May 4th, was devoted to a joint session with the 
Motion Picture Theater Owners of America, and was marked by a collection of 
papers of particular interest to theater operators and managers. The session 

395 



396 HIGHLIGHTS OF SEMI- ANNUAL MEETING 

opened with the paper by D. E. Hyndman, Engineering Vice-President of the 
Society, on "Motion Picture Standards in Wartime," a matter of vital interest 
in the maintenance of high-quality operation of the theater and in paving the way 
for further development after the war. With the thought in mind of possible 
air-raids or other causes of excitment and fear in these parlous times, the paper 
by Dr. Walter Cutter, of the Center for Safety Education, New York University, 
aroused considerable interest and was followed by lengthy discussion. Talks by 
Terry Ramsaye, of the Motion Picture Herald, and William C. Formby, of Box- 
office, and a round table conference by members of the SMPE Sub-Committee 
on Theater Protection completed the remainder of the Exhibitors' Session. 

In the evening, through the courtesy of Miss Iris Barry, Curator of the Film 
Library of the Museum of Modern Art, and Mr. E. F. Kerns, technical director 
of the Film Library, members of the Society were treated to an extremely 
interesting compilation of Nazi propaganda films from the archives of the 
Museum, in demonstration of the powerful uses to which motion pictures may 
be put. The Society expresses its appreciation to the Museum and to Miss 
Barry and Mr. Kerns for this valuable and interesting addition to the program. 

Wednesday morning (May 5th) was devoted to a group of papers on 16-mm 
production, including the report of the Committee on Non-Theatrical Equipment, 
A feature of the afternoon session were two papers by members of The National 
Archives, Washington, and the Library of Congress. The great problem of cata- 
loguing the enormous quantity of film now coming into the National Archives was 
discussed by Capt. John G. Bradley, followed by a description of the cataloguing 
methods that have recently been introduced. Howard L. Walls, of the Library 
of Congress, next described the discovery of a great quantity of paper prints of 
very early motion pictures, dating back as far as 1897, in a paper entitled the 
"Film Incunabula in the Library of Congress." This was followed by a presen- 
tation by Carl L. Gregory on the resurrection of these early motion picture paper 
prints, and their conversion into the 35-mm films that were projected at the con- 
clusion of the paper. Outstanding among these pictures were scenes of the 
funeral cortege of President McKinley, and The Magician by Melies. 

The evening of Wednesday, May 5th, was devoted to the Fifty-Third Semi- 
Annual Banquet of the Society, held in the Georgian Room of the Hotel. 

With the exception of the first two papers, the entire morning and afternoon 
sessions of Thursday, May 6th, were devoted to presentation by members of the 
Armed Forces. A group of ten papers in the afternoon described in extense the 
motion picture activities of the U. S. Army Signal Corps, of the Army Service 
Forces. The titles of, the papers are given on p. 392. 

The Fifty-Third Semi-Annual Meeting closed on Thursday evening with an 
extremely interesting lecture by Ralph M. Evans, of the Eastman Kodak Com- 
pany, on "Visual Processes and Color Photography," which was illustrated by 
more than one hundred slides and prints. 

The Society wishes to acknowledge its gratitude to the large number of persons 
and companies who collaborated in providing the various facilities for the Meet- 
ing. Acknowledgment is due also to the Capitol Theater, the Radio City Music 
Hall, the Roxy Theater, Warner's Strand and Hollywood Theaters, and the 
Paramount Theater for the passes issued to SMPE delegates during the dates of 
the Meeting. 



JOURNAL 

OF THE SOCIETY OF 

MOTION PICTURE ENGINEERS 




AUTHOR AND CLASSIFIED 
INDEXES 

VOLUME XL 
JANUARY-JUNE, 1943 



AUTHOR INDEX, VOLUME XL 



JANUARY TO JUNE, 1943 



Author 
BEERS, G. L. 

BEERS, G. L. 

(and BELAR, H.) 
BEERS, G. L. 

(and SINNETT, C. M.) 
BELAR, H. 

(and BEERS, G. L.) 
BRADLEY, J. G. 
BUB, G. L. 

CRABTREE, J. I. 

(and EATON, G. T.) 
DAVID, M. S. 

EATON, G. T. 

(and CRABTREE, J. I.) 
EDOUART, F. 

EVANS, R. M. 

(and HANSON, W. T., 
and GLASOE, P. K.) 

EVANS, R. M. 

(and HANSON, W. T., 
and GLASOE, P. K.) 

GLASOE, P. K. 

(and HANSON, W. T., 
and EVANS, R. M.) 

GLASOE, P. K. 

(and HANSON, W. T., 
and EVANS, R. M.) 

HANDLEY, C. W. 

(and LINDERMAN, R. G 
and RODGERS, A.) 

HANSON, W. T. 

(and EVANS, R. M., 
and GLASOE, P. K.) 

398 



Issue Page 

The Focusing View-Finder in Tele- 
vision Cameras Mar. 181 
Frequency Distortion in Loud Speakers April 207 

Some Recent Developments in Record- 
Reproducing Systems April 222 

Frequency Modulation in Loud Speak- 
ers April 207 

Motion Pictures and the War Effort May ' 281 

Sound and Projection Equipment in 

War Department Theaters Jan. 35 

Washing Photographic Prints and 

Films in Sea Water June 380 

Sixteen-Mm Motion Pictures and the 

War Effort May 296 

Washing Photographic Films and 

Prints in Sea Water June 380 

The Paramount Transparency Process 

Projection Equipment June 368 

Copper and Sulfide in Developers Feb. 88 



Factors Affecting the Accumulation of 
Iodide in Used Photographic De- 
velopers Feb. 

Copper and Sulfide in Developers Feb. 



97 



Factors Affecting the Accumulation of 
Iodide in Used Photographic De- 
velopers Feb. 97 

Illumination in Motion Picture Pro- 
duction June 333 



Copper and Sulfide in Developers 



Feb. 88 



INDEX 



399 



Author 
HANSON, W. T. 

(and EVANS, R. M., 
and GLASOE, P. K.) 
HILLIARD, J. K. 

ISAAC, L. B. 

IVES, C. E. 

(and JENSEN, E. W.) 

JENSEN, E. W. 
(and IVES, C. E.) 

KICZALES, M. D. 

LlNDERMAN, R. G. 

(and HANDLEY, C. W., 
and RODGERS, A.) 
MATHEWS, N. 
MILLER, W. C. 

MURRAY, R. B. 

RODGERS, A. 

(and LINDERMAN, R. G. 

and HANDLEY, C. W.) 
SERSEN, F. M. 
SINNETT, C. M. 

(and BEERS, G. L.) 
TRAVIS, C. M. 

WELPLEY, C. 



Issue Page 

Factors Affecting the Accumulation of 
Iodide in Used Photographic De- 
velopers Feb. 97 

The Variable-Density Film-Recording 

System Used at MGM Studies Mar. 143 

Maintaining Projection Standards in 

War Time Mar. 176 

The Effect of Developer Agitation on 
Density Uniformity and Rate of 
Development Feb. 107 

The Effect of Developer Agitation on 
Density Uniformity and Rate of De- 
velopment Feb. 107 

Heating, Ventilating, and Air-Condi- 

tioning War Department Theaters Jan. 24 

Illumination in Motion Picture Pro- 
duction June 333 

Motion Pictures in Aircraft Production May 291 

The MGM Recorder and Reproducer 

Equipment May 301 

Administration of the United States 

Army Motion Picture Service Jan. 65 

Illumination in Motion Picture Pro- 
duction June 333 

Special Photographic Effects June 374 

Some Recent Developments in Record- 
Reproducing Systems April 222 

The Motion Picture Industry and the 

War Production Board May 273 

Construction of War Department 

Theaters Jan. 4 



CLASSIFIED INDEX, VOLUME XL 

JANUARY TO JUNE, 1943 

Administration 

Administration of the U. S. Army Motion Picture Service, R. B. Murray, 
No. 1 (Jan.), p. 52. 

Air-Conditioning 

Heating, Ventilating, and Air-Conditioning War Department Theaters, M. D. 
Kiczales, No. 1 (Jan.), p. 24. 

Army, U. S., Motion Picture Service 

(See U. S. Army) 

Cameras 

The Focusing View-Finder in Television Cameras, G. L. Beers, No. 3 (March), 
p. 181. 

Civilian Defense 

Report of the Theater Engineering Committee, No. 2 (Feb.), p. 71. 

Color 

American War Standard Specification and Description of Color, No. 5 (May) , 
p. 277. 

Committee Reports 

Theater Engineering Committee (Sub-Committees on Projection Practice, 
Civilian Defense, and Screen Brightness), No. 2 (Feb.), p. 71. 

Conservation 

Report of the Theater Engineering Committee, No. 2 (Feb.), p. 71. 

Developers 

Copper and Sulfide in Developers, R. M. Evans, W. T. Hanson, and P. K. 
Glasoe, No. 2 (Feb.), p.. 88. 

Factors Affecting the Accumulation of Iodide in Used Photographic Developers, 
R. M. Evans, W. T. Hanson, and P. K. Glasoe, No. 2 (Feb.), p. 97. 

The Effect of Developer Agitation on Density Uniformity and Rate of Develop- 
ment, C. E. Ives and E. W. Jensen, No. 2 (Feb.), p. 107. 

Disc Recording 

Some Recent Developments in Record-Reproducing Systems, G. L. Beers and 
C. M. Sinnett, No. 4 (April), p. 222. 

Distortion 

Frequency Modulation Distortion in Loud Speakers, G. L. Beers and H. 
Belar, No. 4 (April), p. 207. 

400 



INDEX 401 

Film Conservation 

Report of the Theater Engineering Committee, No. 2 (Feb.), p. 71. 

Frequency Modulation 

Frequency Modulation Distortion in Loud Speakers, G. L. Beers and H. Belar, 
No. 4 (April), p. 207. 

General 

The United States Army Motion Picture Service, No. 1 (Jan.), p. 3. 
Report of the Theater Engineering Committee, No. 2 (Feb.), p. 71. 
Maintaining Projection Standards in War Time, L. B. Isaac, No. 3 (March), 

p. 176. 
The Motion Picture Industry arid the War Production Board, C. M. Travis, 

No. 5 (May), p. 273. 

Motion Pictures and the War Effort, J. G. Bradley, No. 5 (May), p. 281. 
Motion Pictures in Aircraft Production, N. Mathews, No. 5 (May), p. 291. 
Sixteen-Millimeter Motion Pictures and the War Effort, M. S. David, No. 5 

(May), p. 296. 

Heating 

Heating, Ventilating, and Air-Conditioning War Department Theaters, M. D. 
Kiczales, No. 1 (Jan.), p. 24. 

Illumination 

Illumination in Motion Picture Production, R. G. Linderman, C. W. Handley, 
and A. Rodgers, No. 6 (June), p. 333. 

Loud Speakers 

Frequency Modulation Distortion in Loud Speakers, G. L. Beers and H. Belar, 
No. 4 (April), p. 207. 

Non-Theatrical 

(See Sixteen-Mm Motion Pictures) 

Processing 

Copper and Sulfide in Developers, R. M. Evans, W. T. Hanson, and P. K. 
Glasoe, No. 2 (Feb.), p. 88. 

Factors Affecting the Accumulation of Iodide in Used Photographic Developers, 
R. M. Evans, W. T. Hansen, and P. K. Glasoe, No. 2 (Feb.), p. 97. 

The Effect of Developer Agitation on Density Uniformity and Rate of De- 
velopment, No. 2 (Feb.), p. 107. 

Washing Photographic Films and Prints in Sea Water, G. T. Eaton and J. I. 
Crabtree, No. 6 (June), p. 380. 

Production 

The Variable-Density Film-Recording System Used at MGM Studios, J. K. 

Hilliard, No. 3 (March), p. 143. 
The MGM Recorder and Reproducer Equipment Units, W. C. Miller, No. 5 

(May), p. 301. 
Illumination in Motion Picture Production, R. G. Linderman, C. W. Handley, 

and A. Rodgers, No. 6 (June), p. 333. 



402 INDEX [J. s. M. p. E. 

Special Photographic Effects, F. M. Sersen, No. 6 (June), p. 374. 
The Paramount Transparency Process Projection Equipment, F. Edouart, 
No. 6 (June), p. 368. 

Projection 

Sound and Projection Equipment in War Department Theaters, G. L. Bub, 

No. 1 (Jan.), p. 35. 

Report of the Theater Engineering Committee, No. 2 (Feb.), p. 71. 
Maintaining Projection Standards in War Time, L. B. Isaac, No. 3 (March), 

p. 176. 

Screen Brightness 

Report of the Theater Engineering Committee, No. 2 (Feb.), p. 71. 

Sea Water 

Washing Photographic Films and Prints in Sea Water, G. T. Eaton and J. I. 
Crabtree, No. 6 (June), p. 380. 

Sixteen-Mm Motion Pictures 

Motion Pictures in Aircraft Production, N. Mathews, No. 5 (May), p. 291. 
Sixteen-Mm Motion Pictures and the War Effort, M. C. David, No. 5 (May), 
p. 296. 

Sound Recording and Reproduction 

Sound and Projection Equipment in War Department Theaters, G. L. Bub, 

No. 1( Jan.), p. 35. 
The Variable-Density Film Recording System Used at MGM Studios, J. K. 

Milliard, No. 3 (March), p. 143. 
Frequency Modulation Distortion in Loud Speakers, G. L. Beers and H. Belar, 

No. 4 (April), p. 207. 
Some Recent Developments in Record-Reproducing Systems, G. L. Beers and 

C. M. Sinnett, No. 4 (April), p. 222. 
The MGM Recorder and Reproducer Equipment Units, W. C. Miller, No. 5 

(May), p. 301. 

Special Effects Photography 

Special Photographic Effects, F. M. Sersen, No. 6 (June), p. 374. 
The Paramount Transparency Process Projection Equipment, F. Edouart, 
No. 6 (June), p. 368. 

Standards 

Maintaining Projection Standards in War Time, L. B. Isaac, No. 3 (March), 

p. 176. 
American War Standard Specification and Description of Color, No. 5 

(May), p. 277. 

Studio Equipment 

The Variable-Density Film-Recording System Used at MGM Studies, J. K. 

Milliard, No. 3 (March), p. 143. 

The MGM Recorder and Reproducer Equipment Units, W. C. Miller, No. 5 
(May), p. 301. 



June, 1943] INDEX 403 

Illumination in Motion Picture Production, R. G. Linderman, W. C. Handley, 

and A. Rodgers, No. 6 (June), p. 333. 

Special Photographic Effects, F. M. Sersen, No. 6 (June), p. 374. 
The Paramount Transparency Process Projection Equipment, F. Edouart, 

No. 6 (June), p. 368. 

Transparency Process 

The Paramount Transparency Process Projection Equipment, F. Edouart, 
No. 6 (June), p. 368. 

Television 

The Focusing View-Finder in Television Cameras, No. 3 (March), p. 181. 

Theaters 

Construction of War Department Theaters, C. Welpley, No. 1 (Jan.), p. 4. 
Heating, Ventilating, and Air-Conditioning War Deparment Theaters, M. D. 

Kiczales, No. 1 (Jan.), p. 24. 
Sound and Projection Equipment in War Department Theaters, G. L. Bub, 

No. 1( Jan.), p. 35. 
Report of the Theater Engineering Committee, No. 2 (Feb.), p. 71. 

U. S. Army Motion Picture Service 

The United States Army Motion Picture Service, No. 1 (Jan.), p. 3. 
Construction of War Department Theaters, C. Welpley, No. 1 (Jan.), p. 3. 
Heating, Ventilating, and Air-Conditioning War Department Theaters, M. D. 

Kiczales, No. 1 (Jan.), p. 24. 
Sound and Projection Equipment in War Department Theaters, G. L. Bub, 

No. 1 (Jan.), p. 35. 
Administration of the U. S. Army Motion Picture Service, R. B. Murray, No. 1 

(Jan.), p. 64. 

Ventilation 

Heating, Ventilating, and Air-Conditioning War Department Theaters, M. D. 
Kiczales, No. 1 (Jan.), p. 24. 

View Finders 

The Focusing View-Finder in Television Cameras, G. L. Beers, No. 3 (March) , 
p. 181. 

War Department 

(See U. S. Army) 

War Production Board 

The Motion Picture Industry and the War Production Board, C. M. Travis, 
No. 5 (May), p. 273. 

Washing Photographic Materials 

Washing Photographic Films and Prints in Sea Water, G. T. Eaton and J. I. 
Crabtree, No. 6 (June), p. 380. 



MEMBERS OF THE SOCIETY 

LOST IN THE SERVICE OF 

THEIR COUNTRY 



FRANKLIN C. GILBERT 



ISRAEL H. TILLES 



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